I'm posting this continuation of a thread originally posted in Jun of ‘07 out of consideration for those who find it takes a considerable amount of time to load because of its length. It has garnered much more attention than I ever imagined it would, and has been great fun - a wonderful catalyst in the forging of new friendships and in increasing my list of acquaintances with growing interests similar to mine. The same information was posted on a competing forum site in '05. Still very active, it has received the attention of just under 1,500 posts as I write.
The forum and email exchanges that stem so often from the subject are, in themselves, enough to make me hope the subject continues to pique interest and the exchanges provide helpful information. Most of the motivation for posting this thread again comes from the participants’ reinforcement of the idea that some of the information provided in good-spirited collective exchange will make some degree of difference in the level of satisfaction of a considerable fraction of the readers’ growing experience. It is difficult for me to talk about the thread in an objective manner without a few taking it as my being boastful, but if I may be brief, I will just say there have been enough growers who have expressed the opinion that the information in the thread has been pivotal in their progression as container gardeners for me to finally bring myself to say that I feel the information is valuable.
This thread is not about recipes, though they are widely discussed, it is about concepts and a way of approaching gardening in containers that varies from what we might consider current convention. I'll let the success stories and enthusiasm in the previous postings, and likely this one, speak for themselves.
I'll provide links to the previous threads at the end of what I have written - in case you have interest in reviewing them. Thank you for taking the time to look into this subject - I hope that any/all who take the time to read it, find something interesting and helpful in it. I know it's long, but I hope you find it worth the read. Most of all, I hope it stimulates discussion and questions. Please excuse the lengthy introduction, which I'll conclude by thanking everyone who has shown interest and participated in the discussions. I'll look forward to your input and questions.
Container Soils - Water Movement and Retention - A Discussion About Soils
As container gardeners, our first priority should be to insure the soils we use are adequately aerated for the life of the planting, or in the case of perennial material (trees, shrubs, garden perennials), from repot to repot. Soil aeration/drainage is the most important consideration in any container planting. Soils are the foundation that all container plantings are built on, and aeration is the very cornerstone of that foundation. Since aeration and drainage are inversely linked to soil particle size, it makes good sense to try to find and use soils or primary components with particles larger than peat. Durability and stability of soil components so they contribute to the retention of soil structure for extended periods is also extremely important. Pine and some other types of conifer bark fit the bill nicely, but I’ll talk more about various components later.
What I will write also hits pretty hard against the futility in using a drainage layer of coarse materials as an attempt to improve drainage. It just doesn't work. All it does is reduce the total volume of soil available for root colonization. A wick can be employed to remove water from the saturated layer of soil at the container bottom, but a drainage layer is not effective. A wick can be made to work in reverse of the self-watering pots widely being discussed on this forum now.
Since there are many questions about soils appropriate for use in containers, I'll post basic mix recipes later, in case any would like to try the soil. It will follow the Water Movement information.
Consider this if you will:
Soil fills only a few needs in container culture. Among them are: Anchorage - A place for roots to extend, securing the plant and preventing it from toppling. Nutrient Retention - It must retain enough nutrients in available form to sustain plant systems. Gas Exchange - It must be sufficiently porous to allow air to move through the root system and by-product gasses to escape. Water - It must retain water enough in liquid and/or vapor form to sustain plants between waterings. Most plants can be grown without soil as long as we can provide air, nutrients, and water, (witness hydroponics). Here, I will concentrate primarily on the movement of water in soil(s).
There are two forces that cause water to move through soil - one is gravity, the other capillary action. Gravity needs little explanation, but for this writing I would like to note: Gravitational flow potential (GFP) is greater for water at the top of the container than it is for water at the bottom. I'll return to that later. Capillarity is a function of the natural forces of adhesion and cohesion. Adhesion is water's tendency to stick to solid objects like soil particles and the sides of the pot. Cohesion is the tendency for water to stick to itself. Cohesion is why we often find water in droplet form - because cohesion is at times stronger than adhesion; in other words, water’s bond to itself can be stronger than the bond to the object it might be in contact with; in this condition it forms a drop. Capillary action is in evidence when we dip a paper towel in water. The water will soak into the towel and rise several inches above the surface of the water. It will not drain back into the source, and it will stop rising when the GFP equals the capillary attraction of the fibers in the paper.
There will be a naturally occurring "perched water table" (PWT) in containers when soil particulate size is under about .125 (1/8) inch.. This is water that occupies a layer of soil that is always saturated & will not drain from the portion of the pot it occupies. It can evaporate or be used by the plant, but physical forces will not allow it to drain. It is there because the capillary pull of the soil at some point will surpass the GFP; therefore, the water does not drain, it is perched. The smaller the size of the particles in a soil, the greater the height of the PWT. This water can be tightly held in heavy (comprised of small particles) soils and ‘perch’ (think of a bird on a perch) just above the container bottom where it will not drain; or, it can perch in a layer of heavy soil on top of a coarse drainage layer, where it will not drain.
Imagine that we have five cylinders of varying heights, shapes, and diameters, each with drain holes, and we fill them all with the same soil mix, then saturate the soil. The PWT will be exactly the same height in each container. This saturated area of the container is where roots initially seldom penetrate & where root problems frequently begin due to a lack of aeration. Water and nutrient uptake are also compromised by lack of air in the root zone. Keeping in mind the fact that the PWT height is dependent on soil particle size and has nothing to do with height or shape of the container, we can draw the conclusion that: Tall growing containers will always have a higher percentage of unsaturated soil than squat containers when using the same soil mix. The reason: The level of the PWT will be the same in each container, with the taller container providing more usable, air holding soil above the PWT. From this, we could make a good case that taller containers are easier to grow in.
A given volume of large soil particles has less overall surface area when compared to the same volume of small particles and therefore less overall adhesive attraction to water. So, in soils with large particles, GFP more readily overcomes capillary attraction. They drain better. We all know this, but the reason, often unclear, is that the height of the PWT is lower in coarse soils than in fine soils. The key to good drainage is size and uniformity of soil particles. Mixing large particles with small is often very ineffective because the smaller particles fit between the large, increasing surface area which increases the capillary attraction and thus the water holding potential. An illustrative question: How much perlite do we need to add to pudding to make it drain well?
We have seen that adding a coarse drainage layer at the container bottom does not improve drainage. It does though, reduce the volume of soil required to fill a container, making the container lighter. When we employ a drainage layer in an attempt to improve drainage, what we are actually doing is moving the level of the PWT higher in the pot. This simply reduces the volume of soil available for roots to colonize. Containers with uniform soil particle size from top of container to bottom will yield better and more uniform drainage and have a lower PWT than containers using the same soil with drainage layers.
The coarser the drainage layer, the more detrimental to drainage it is because water is more (for lack of a better scientific word) reluctant to make the downward transition because the capillary pull of the soil above the drainage layer is stronger than the GFP. The reason for this is there is far more surface area on soil particles for water to be attracted to in the soil above the drainage layer than there is in the drainage layer, so the water perches. I know this goes against what most have thought to be true, but the principle is scientifically sound, and experiments have shown it as so. Many nurserymen employ the pot-in-pot or the pot-in-trench method of growing to capitalize on the science.
If you discover you need to increase drainage, you can simply insert an absorbent wick into a drainage hole & allow it to extend from the saturated soil in the container to a few inches below the bottom of the pot, or allow it to contact soil below the container where the earth acts as a giant wick and will absorb all or most of the perched water in the container, in most cases. Eliminating the PWT has much the same effect as providing your plants much more soil to grow in, as well as allowing more, much needed air in the root zone.
In simple terms: Plants that expire because of drainage problems either die of thirst because the roots have rotted and can no longer take up water, or they starve/"suffocate" because there is insufficient air at the root zone to insure normal water/nutrient uptake and root function.
Bark fines of fir, hemlock or pine, are excellent as the primary component of your soils. The lignin contained in bark keeps it rigid and the rigidity provides air-holding pockets in the root zone far longer than peat or compost mixes that too quickly break down to a soup-like consistency. Conifer bark also contains suberin, a lipid sometimes referred to as nature’s preservative. Suberin, more scarce as a presence in sapwood products and hardwood bark, dramatically slows the decomposition of conifer bark-based soils. It contains highly varied hydrocarbon chains and the microorganisms that turn peat to soup have great difficulty cleaving these chains.
To confirm the existence of the PWT and how effective a wick is at removing it, try this experiment: Fill a soft drink cup nearly full of garden soil. Add enough water to fill to the top, being sure all soil is saturated. Punch a drain hole in the bottom of the cup and allow the water to drain. When drainage has stopped, insert a wick into the drain hole . Take note of how much additional water drains. Even touching the soil with a toothpick through the drain hole will cause substantial additional water to drain. The water that drains is water that occupied the PWT. A greatly simplified explanation of what occurs is: The wick or toothpick "fools" the water into thinking the pot is deeper than it is, so water begins to move downward seeking the "new" bottom of the pot, pulling the rest of the water in the PWT along with it. If there is interest, there are other simple and interesting experiments you can perform to confirm the existence of a PWT in container soils. I can expand later in the thread.
I always remain cognizant of these physical principles whenever I build a soil. I haven’t used a commercially prepared soil in many years, preferring to build a soil or amend one of my 2 basic mixes to suit individual plantings. I keep many ingredients at the ready for building soils, but the basic building process usually starts with conifer bark and perlite. Sphagnum peat plays a secondary role in my container soils because it breaks down too quickly to suit me, and when it does, it impedes drainage and reduces aeration. Size matters. Partially composted conifer bark fines (pine is easiest to find and least expensive) works best in the following recipes, followed by uncomposted bark in the larger than 3/8" range.
Note that there is no sand or compost in the soils I use. Sand, as most of you think of it, can improve drainage in some cases, but it reduces aeration by filling valuable macro-pores in soils. Unless sand particle size is fairly uniform and/or larger than about ½ BB size I leave it out of soils. Compost is too unstable for me to consider using in soils. The small amount of micro-nutrients it supplies can easily be delivered by one or more of a number of chemical or organic sources.
My Basic Soils
5 parts pine bark fines
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime (or gypsum in some cases)
controlled release fertilizer (if preferred)
micro-nutrient powder, other continued source of micro-nutrients, or fertilizer with all nutrients - including minors
2-3 cu ft pine bark fines
5 gallons peat
5 gallons perlite
2 cups dolomitic (garden) lime (or gypsum in some cases)
2 cups CRF (if preferred)
1/2 cup micro-nutrient powder (or other source of the minors)
3 gallons pine bark
1/2 gallon peat
1/2 gallon perlite
4 tbsp lime (or gypsum in some cases)
1/4 cup CRF (if preferred)
micro-nutrient powder (or other source of the minors)
I have seen advice that some highly organic (practically speaking - almost all container soils are highly organic) container soils are productive for up to 5 years or more. I disagree and will explain why if there is interest. Even if you were to substitute fir bark for pine bark in this recipe (and this recipe will long outlast any peat based soil) you should only expect a maximum of two to three years life before a repot is in order. Usually perennials, including trees (they're perennials too) should be repotted more frequently to insure vigor closer to their genetic potential. If a soil is desired that will retain structure for long periods, we need to look more to inorganic components. Some examples are crushed granite, pea stone, coarse sand (see above - usually no smaller than ½ BB size in containers, please), Haydite, lava rock (pumice), Turface or Schultz soil conditioner, and others.
For long term (especially woody) plantings and houseplants, I use a soil that is extremely durable and structurally sound. The basic mix is equal parts of pine bark, Turface, and crushed granite.
1 part uncomposted pine or fir bark
1 part Turface
1 part crushed granite
1 Tbsp gypsum per gallon of soil
CRF (if desired)
Source of micro-nutrients or use a fertilizer that contains all essentials
I use 1/8 -1/4 tsp Epsom salts per gallon of fertilizer solution when I fertilize (check your fertilizer - if it is soluble, it is probable it does not contain Ca or Mg.
By the way, if you remove about half of the asterisks (***********) it will allow the thread to be viewed w/out having to scroll back and forth. In other words it will keep the page more compact and more easily read.
Those "self-watering" pots and the like are very expensive and not very effective. On effectiveness first --it will be YOUR-self who waters them. Just because you put in an extra quart or gallon doesn't mean they won't dry out. Even if the extra water provides the proper moisture level consistently --let's assume it does-- if you are lulled into thinking you don't have to water, you got trouble.
I also think that Al will say a.) the better use of the pot-space the devices occupy, at the bottom of your pots, is best used as more space for soil in which roots can grow, with proper watering and b.) these things don't change the laws of physics --you'll still have a PWT level, it'll just be higher up in your pot by the exact depth of the water level in the device.
On expense --for the price of two of those pots, $25, you can put together a simple irrigation system that will let you water all your plants in a couple minutes each day. For the price of five or six, you can put one together with an automatic timer that provides two different timing/amount patterns.
Overall, with proper watering (by and or by irrigation), you and your plants will be better off with good soil to the bottom of your pots instead of an expensive, hidden reservoir where roots could otherwise be growing.
Searching for pine or fir bark online (having had no success finding it locally), I came across a website selling fir bark by the 2 cu ft bag. They offer several sizes. The "fine" is 1/16 to 3/16, whereas "small" is 3/16 to 3/8 inch. I ordered small. Was that the right choice, do you think? This is for making up your last recipe, for woody plants. Thank you.
Either will work well if you're using the granite and screened Turface. The mix tends to take on the physical properties of the two ingredients closest in size. I use 1/8-1/4, but I think that if I could get it, I would choose the fine, 1/6-3/16 as a better choice for my purposes, probably yours, too; but don't be disheartened - it's going to work fine, and you'll be well pleased.
You've decided on a fertilizer regimen?
Have a good Memorial Day. Remember those who gave all.
I'm running a bit late here, but I had to say thanks so much for the revised edition.
This is valuable information that should be given to every garden center worker, plant magazine editor, & garden forum (LOL), to stop the "old wive's tales" concerning container culture. (Such as using pot shards for "drainage", using crazy materials on the bottom of pots to save potting soil, or "recycling" medium by just adding a bit of new to the old. Aiee!)
And many, many, thanks for making the science behind it understandable to the layperson too. That's no easy task !
This container soils part III should probably be a sticky like the other two, otherwise it disappears and is hard to find. Is that something you do, or the folks at Dave's Garden?
As for fertilizer regimen, I'm doing a mix. In the pots that are far from the house that I water by hose, I'm using continuous release pellets. In the pots nearby, I put in a small sprinkle of pellets as a safety margin but will add liquid Dynagro 7-9-5 also (on a sadly erratic schedule). I know that isn't the right nutrient proportions (I can't remember what you said is the best balance, and that post isn't as easy to find as the soils post) but I haven't, so far, found the Dynagro that you recommend.
My ginkgo bonsai was repotted this spring with your woody plant mix. I've been amazed at how well it retains moisture--it doesn't seem like it would, by the look and feel of the mix--but it does. I'm currently watering it about every 3-4 days. (I use a rock on the soil to tell when it needs watering. If the soil under the rock is dry, I water.) The plant is thriving. I only had enough for a few plants with the "good" mix that I did right. Then I ran out of pine bark and substituted what I could get locally and used that mix for a number of Japanese maples, and that is better than the potting soil I used to use, but not as good as the pot the bonsai is in. Hence my order for properly graded fir bark online, despite the fact postage costs as much as the bark!
I'm not sure how one gets a thread to become a sticky - never done it before. I've had others ask if it was ok if they write admin & request it (sticky) if the information seems valuable enough. I think that's how all the threads I have as stickies got to be that way, but some of them just showed up one day, stuck to the top of a forum ...
About the bark - if you have any places near you that sell orchids and orchid supplies, you might check with them for the prescreened fir bark. I get to CHI quite frequently, and I'll often take my truck and pick up 10-20 3 cu ft bags @ around $17 each, but you could also screen uncomposted pine bark & use the fines in the 5:1:1 mix for veggies & flowery stuff.
I prefer fertilizers in the 3:1:2 ratio for almost everything I grow in containers. It provides nutrients in as close to the ratio plants actually use, which allows you to keep TDS/EC (basically salts level) at the lowest levels possible w/o nutritional deficiencies - a decided advantage. Some examples of 3:1:2 ratios include MG, Peter's, Schultz, others in granular soluble 24-8-16 - MG liquid 12-4-8 - Dyna-Gro's Foliage-Pro liquid 9-3-6 (preferred).
I often look for the thread about fertilizing containers too, but it's hard to find with the search function not working. I'll try again.
Quoting: Some examples of 3:1:2 ratios include MG, Peter's, Schultz, others in granular soluble 24-8-16 - MG liquid 12-4-8 - Dyna-Gro's Foliage-Pro liquid 9-3-6 (preferred).
I have to add that I used Dyna-Gro Foliage-Pro 9-3-6 all this winter and spring (as per Al's suggestion) and I am really impressed by the health of my container plants, who made it through the winter in my sun room and flourished!
Also used Dyna-Gro Neem Oil and was very pleased.
Yes, I've been using the 9-3-6 on virtually all my containerized plants for the last several years, and I can say it's performed better than any fertilizer I've ever used. It really does take all the guesswork out of supplying your plant's nutrition.
Pirl was kind enough to let me know in a D-mail that the search function is now alive and well, so here is the link to the thread about fertilizing containerized plants:
It turned out the people at Roberts Flower Supply hadn't yet shipped my bark and kindly substituted the finest grade for the "small" grade. It arrived today and it is GREAT. I'm so pleased. I now have all ingredients in place to make a decent-sized batch of the woody mix. The funny part is they included a printed catalog with my order, and wouldn't you know it, they also carry the Dyna-Gro Foliage fertilizer. If I'd only realized, I could have had them add that to the box and probably wouldn't have paid any more postage...oh well, next time.
Puddle, I grew up in Elyria, Oberlin, and Lorraine, till age 11. I remember going to North Ridgeville and grandma talking about it all the time but don't know why. She was a gardener too. I got it from her. Funny how when she moved here to the desert from Ohio, she thought the desert land she lived on was land that nobody had pulled weeds. She lived on some people's property that was 5 acres of Caleche soil and hard pan. One day she was out there looking like death and said Dawn will you please help me pull these weeds. I was 18 or 19 and said Oh no grandma I have to go somewhere, but laughed that she had mostly hand weeded 5 acres herself and did not know it would come back next year again. I get weepy thinking of that day. I wished I had helped her or offered to come back when it was not so hot to help her later.
Hi, guys. Please don't think your input and comments aren't welcome, because they are, but if we could just try to keep them focused on the subject - so others reading through the thread for information don't have to sort through the OT conversations. Thank you.
Mr. tapla/Al: where are u? Haven't seen very recent posts... I really appreciate all your info and expertise.
In both 5-1-1 and gritty mix: does using FoliagePro 9-3-6 eliminate the addition of lime and/or gypsum? I don't seem to grasp this aspect of the mixes. I'm using containers for a number of cacti/succulents and may try some fall veggies - brussel sprouts, kale, maybe others.
Also, in a thread regarding repotting, I think, a pre-bonsai plant, you had a picture showing the wick and screen setup in the bottom of the pot; what is the crosswise piece of what looks like clothes hanger wire?
I only come around when someone else has comments or needs help - always avoid bumping my own threads. ;o)
I tried several plants this year with only FP, using the gritty mix, and they seem fine, but the 5:1:1 mix should be limed to bring pH up. The pH of the gritty mix is higher than the pre-limed 5:1:1 mix, which was the reason for using the gypsum as a lime source and Epsom salts as the Mg source (they don't raise pH). When using fertilizers that DO NOT contain Ca and/or MG, it's important that you take measures to make them available, so read the labels.
If you're still confused, let me know & I'll go into detail.
The wire is like a staple pin-stitch made from a scrap of bonsai wire that goes through the mesh & outside of the pot to hold the mesh securely in place.
Thanks, Al. Man, I hate to belabor the topic, but ... I needed more grit and in the interest of time/money/gas, etc. bought some MannaPro (no size info that I could find) and it's generally larger than gran-i-grit. I've screened it thru 1/4 (most went thru), then 1/8 (and got a good amount there) and then insect/tea strainer to get rid of the tiny stuff. The 1/4-1/8 seems larger than the gran-i-grit -- ok to use it in gritty mix?
Also, I've mixed two 5-gal. buckets of 5-1-1 using bark, peat & turface (to avoid perlite) and it seems awfully "fine". I did read your post regarding leaving out peat in a situation like this, but it's now that I my mix may be too fine -- what would you suggest to add at this point? I will most likely be making more 5-1-1 in the future, mainly for SWC of some fall veggies. Thanks again, Al; you're a very patient man!
They should have a smaller size grit that would be more appropriate. I use #2 cherrystone, which tends to run a little larger than grower size in the Gran-I-Grit. I'd say it's about 3/32 - 3/16. You can use larger, but here's the deal. When you use disparate sizes in your material, it has more of a tendency to separate, and the soil takes on the characteristics of the two ingredients that are closest in size. IOW you can use large grit, but if you bark is also large, the soil takes on (primarily) the characteristics of the bark and grit.
[Not snotty here. ;o)] I'm not selling you on a soil, I'm selling you on a concept. That is, on 'a' soil that has very good aeration for the life of the planting. How I got there took a lot of consideration & experimenting. The ingredients I use are the best I've found at what they do for the soil, but I realize there will always be the need for substitutes, and tinkerers trying to improve on the soil to suit their purposes, which is actually what I intended. I wasn't pushing the recipe, rather, the concept. If you understand the concept & what all the different ingredients (can) bring to the table, you should be able to fix any problems. I'm also usually around to help where I can.
Suggestion: If you find the larger grit makes for too little water retention, adjust the amount of grit:Turface, keeping the bark fraction at no more than 1/3 of the o/a mix. Try 4 Turface, 3 bark, 2 grit, or something similar. Play with it until it suits you. Some are tempted to leave the Turface unscreened to increase water retention, or even add in peat or similar. This eliminates the very reason the gritty mix works so well and reintroduces a PWT to deal with. The soil is made with the water retentive screened Turface and grit that holds no water, other than what it holds in its surface, so you adjust water retention w/o having to deal with a PWT.
The peat is in the 5:1:1 mix to adjust water retention. If you feel the soil you made is too fine & will support too much perched water, then add more bark & perlite to what you have, along with a small fraction of lime. After you've used the soil for a year, you'll be able to tell what you need to do by simply looking at the bark you have to work with. Small bark with lots of fines requires little or no peat, while a larger bark, especially if it's pretty fresh, might require more peat than a 5:1:1 ratio.
I didn't name the soil, others did - both of them, so the 5:1:1 and the 1:1:1 ratios are just my initial guidelines. The recipe gives you a starting point ... a fledgling bird - the wings come with understanding the concept. ;o)
I've repotted two plants that I put in a mix that turned out to be too coarse. My bark was pretty large and I had no peat initially. Had to take the plants out (one was a bamboo, the other a ming aralia), mix in some peat, and try again. Sound like you are saying it would have been better to add more turface. In any case, things seem to be going better now, I'm not finding the leaves all curled within a day of watering.
I don't know what your mix was, but if it was a variation of the gritty mix, it probably would have been better to increase the amount of screened Turface, rather than add the peat. FWIW - I have about 250-300 plants in some minor variation of the 1:1:1 gritty mix, and I don't have issues with water retention, though I do have to water more frequently than if I was using a bagged peat-based soil.
It's always better to get the job done with some consistency. IOW - if you mix sand with boulder-size marbles, you won't have a very good soil from the perspective of physical properties, no matter what ratio of sand:marbles you use, but if you were mixing screened Turface & crushed granite - you get a consistent mixture that stays mixed and that you can vary to adjust water retention.
Your problem sounds like it was related directly to the size of the bark. Reducing the size of the bark would increase water retention and make any peat or Turface you might add more effective.
Al, thanks so much for your input and guidance, especially on adjusting the mix ratios. I just get so frustrated with attempts to locate the ingredients; turface and grit are less of a problem tho my sources are 50-100 miles in opposite directions! The pine bark is the main problem; a big box store website advertised "soil conditioner" but when I got there it was not to be had - they were now selling a "landscape mix" (which I bought) and it turned out to be something I'm not sure I can use. When I lived in the Carolinas it was easier to buy products 'cause the nurseries had displays of their soil amendments and I don't remember so many pre-mixed products either. I thought I had located a source of bark, what they call "regrind" and not composted BUT (you know there'd be a but) they sell only large quantities and if I remember correctly, delivery only, and the place is 350 miles from me...
I've got the screening fairly covered: 1/2, 3/8, 1/4, 1/8 and my trusty tea strainer. You know I'll be back as more questions come up -- right now I'm gonna repot a jade plant and an agave that didn't seem to like what I thought they needed to be planted in (my opinion, of course) and see how they like the gritty mix. Thanks again, Al. You're so very knowledgeable!
I hope this is not too off topic... I've read through these threads over the past year or so but I don't remember this coming up, I apologize if someone has already asked but...
I have a lot of plants in containers and I believe I have a good soil mixture but I am constantly battling weeds in the pots. I try to pull them always when I see them but it seems like a never ending battle. The pots that are topped off with gravel don't have AS big of an issue but its still an issue. I know that part of the fight has to be in the lawn in general but I tell ya these weeds are just having a hay day in my pots. Any words of wisdom for me?
I have lots of problems with oxalis - particularly Oxalis corniculata - the little creeping one with purplish foliage and tiny yellow flowers (if you let it get that far) , Euphorbia maculata (spotted spurge), and Sagina subulata (pearlwort/Irish moss).
I usually just pull the spurge, which comes up roots & all - and doesn't grow back unless it's already seeded out, so pull it when you see it. Sometimes, I pull the pearlwort, but other times I'll spray a little premixed Round-up (or similar) into a small cup & use a small paint brush to daub a little solution on the plants. I always use this technique on the oxalis, as it usually does no good to try to pull it because even if you get the taproot, there are usually stolons & rhizomes left behind in the soil that develop into new plants.
I guess you'll need to develop your own strategy, based on how tenacious the weed is, but keep after them & be sure to get them out of your containers before they seed or get a strong hold. "The price of freedom is eternal vigilance" T.G.
Yes that is truly what you have to do. I try pre-emergent in the late fall and then if any sign of it shows, I use q-tips to brush on the stem of the unwanted creature. I am using this method in my mixes now, and having success, but having troubles finding the right size particles as well.
A couple of days ago on August 30th I re-planted my Colorado blue spruce dwarf weeping variety called 'the blues' into the same 20 x 20 container, but I used a 3 part mix of 1 part potting soil (sphagnum peat moss, perlite, starter charge, dolomitic limestone, calcitic limestone, wetting agent), 1 part lava rock and 1 part pine bark fines to make the soil fast draining. In August we had 9.14 inches of rain which was above average and the potting soil in the container stayed very moist which caused the tips of the blue spruce to turn yellow from too much water since they don't like wet feet. Thankfully the last few days it has been hot, windy, and mostly dry and the forecast calls for more dry weather. It has only been in it's new soil for a couple of days, but it already looks better and hopefully it thrives. I still have it on the east side of the house so it only gets morning sun, but once it gets cooler I will move it to the south side of the house so it can get full sun. Does this sound like a good soil mix for a dwarf blue spuce in a container? (I originally received and planted the spruce a month ago using just potting mix).
It SOUNDS like it should work ok, but w/o some idea about how large the bark & pumice were, it's hard to be any more specific than to offer an encouraging word. ;o) Is the bark on top (in the pic) part of the soil, or is it mulch you added after planting?
The bark and pumice are extremely large for a soil. You want the particles to be around 1/8" or so. The object is to use a mix of soil particles large enough to minimize or eliminate perched water, yet small enough to maximize retention of water that doesn't perch. IOW - you want your soil to hold as much water as possible w/o it perching.
Your plant will probably grow ok, but my concerns are that the potting soil will separate because of the particle size disparity and end up on the bottom of the container, and because of the very large particle size that you'll have trouble keeping the soil moist, particularly the top 2/3.
After I re-planted I kind of had that thought in the back of my mind about the potting soil separating. I wouldn't think it would separate very easily using drip irrigation, but rain storms are another story. I will keep an eye on it and see what happens for now, but I'm thinking I might have to re-plant sooner than I would have needed to if I would have found more ideal products for my specific application.
I'm sorry - I had several windows open & thought I was posting the above pics to another thread - they really have nothing to do with container soils, other than the fact that anything in a container is in the gritty mix.
Hi Al, I have almost wore out a pair of reading glasses following your posts (:0), "BUT I SURE HAVE LEARNT A LOT"
I have lots of pine trees in my yard, and was wondering if I crushed up the bark that is loose and some that the squirrels tear of while climbing
up and down the trees, wil that be ok to use in EB container mix?
Mass is an important consideration in determining how fast something breaks down. We want something that has enough large pieces that it will not break down before roots have almost completely filled the container/soil mass. If the pieces fit the bill based on size, they might work, but the outer layers of pine bark have already been partially broken down. The bark we buy is usually a byproduct of some phase of the lumbering industry and includes the inner bark that has never been exposed to weather & sunlight, so it's much more stable than the outer flakes.
Still, I've never been asked this question, so I'm answering based on my own reasoning. There's nothing to stop you from experimenting, if you have a sufficient volume, and reporting back to us. ;o)
Thanks Tapla, I think after checking my bark I will buy some(:o)
My problem is, I can only find pine bark mulch that does not say fines at lowes.
I guess I will call h/d and see if they have fines.
'Fines' is an adjective, so if you only look for something with 'fines' on the bag, you might by-pass a lot of good material before you find what you need. I use the word 'fines' so you don't get big nuggets. If you know what Sugar-Pops cereal is, I'd say you want bark that has particles from dust size to not much larger than Sugar Pops for the 5:1:1 mix. For the gritty mix, use screened bark from 1/8-3/8 or so in size.
The bark at 3,6,9 o'clock are good for the 5:1:1 mix ... or for the gritty mix if you screen it. What I use for the gritty mix is the pre-screened white fir bark at 12.
Thanks Tapla, so you recomend your 5.1.1. mix for the EB system?
I have read so many posts, I am slightly confused, as I can't retain all I have read (:o(
I would like to thank you for all the time and effort you put into these forums. You should be made an honory member.
Please DO check, Linda, but product varies widely by region. Because of shipping costs, the TX market will likely be served by a different and nearer supplier. I still have my fingers crossed for you, but it's unlikely you'll find the same product @ a TX Lowe's as in NC. :-(
I'm zeroing in by describing it as being no larger than about the size of Sugar Corn Pops cereal. Once I say that, everyone owns up to whether they have it or not. So far the one consensus I'm getting from the local soil companies is that it's very hard to come by, because of how much is lost during grinding it down to that sIze. Seems 5-7 cu ft. grinds down to only 2 cu ft. They lose a lot of product.
"the TX market will likely be served by a different and nearer supplier. I still have my fingers crossed for you, but it's unlikely you'll find the same product @ a TX Lowe's as in NC. "
Yep, that's exactly what I thought, too, Al. I did a search for Texas Lowe's, hoping I could find a local source. The link I gave came from a Lowe's in Baytown, Tex (outside Houston). I sure hope they really have in the store what they showed on their website. It seems like very few pine products are available in parts of the west and mid-west, doesn't it?
Linda, if you click the link I gave then click on "check quantity" it'll give you an inventory on that product for several Lowe's stores around Houston. Hopefully you'll find what you are looking for.
My experience with shopping the Lowe's website -- it showed an inventory of Evergreen soil conditioner so I made the trip only to be told at the store that they had not had that product in quite awhile and were offering a "landscape mix" in place of, which turned out to be too much other stuff with the pine bark. Landscapers Pride makes a soil conditioner that's the best I've found so far, but I've not had great success in locating, other than just happening upon it as I've shopped various smaller plant places.
sheesh...wish I could send ya'll Texans a pallet-load of pine fines. Once you try it you'll be hooked on it. (Al, you should've bought stock in it, all the folks you've gotten addicted to using it you might be rich! *grin)
Southwest Fertilizer here on Bissonet carries Landscaper's Pride. LOTS of it! All the time!
But, I took this picture of some of it when I went on a "Fines" and destroy mission. On the TPF rating scale (Tapla Pine Fines), I believe it got maybe 2 outta 5 stars because it has a high sapwood content and not enough bark...
Hey Shoe, when I lived in the Carolinas I had no idea how much I would appreciate having a source for Nature's Helper and/or other pine products, which I recall being better than what I'm finding now...
Gymgirl, that looks nothing like the Landscapers Pride Soil Conditioner I bought. Yours looks more like the LP bark mulch I use around flower beds.
Living Earth (www.livingearth.net) has a place near the LA state line that sells "fresh pine regrind" which sounds perfect, but it's bulk only, delivered only (if I recall correctly). I plan to call them for details and also to see if they sell to customers who resell. Anyway, it keeps me busy trying to track down all this stuff!!!
I agree. None of what I found looked piney. When I bulled past the young clerks who knew nothing, and got the gray-haired clerk who was knowledgable, the immediate answer was "Probably not. Not much pine around here, mostly fir."
I guess non-Balsam fir might be OK, but there's no way to know.
I was surprised to find so much sapwood, and such big chunks and fine dust in the same bag. Oh, well, if it were graded to size, it would be three times as expensive.
By the way - have many of you gotten pitying looks and "To GROW things in?!? You know you need SOIL to grow things!"
I tried several repetitions of things like "almost hydroponics" and "kind of a soil-less mix" ... then they either got it or decided to humor me. One lady, after scorning the idea, admitted that NURSERIES sometimesw did it because it was lighter to ship, BUT!" (I never found out what the "but" was.
I guess anything different is suspect. Mulch should only be used to mulch, only soil should be used for growing. Kind of binary logic.
But I really scored big in a local Home Depot: many free 3.5" square pots and lots of 5" round pots, and a STACK of web trays! (chortling with glee)
I was promised Evergreen Soil Conditioner at Lowe's and was presented with Happi Gardener pine bark mulch. Again, chunky and some slices but doesn't look like sapwood. The dime-size slices would need to be sifted out and I don't know how much would be lost. But, the larger pieces could be run through a wood chipper? for less loss.
Gymgirl, I finally found my bag of Hapi-Gro called 'landscaper mix' (also from Lowe's) -- "100% organic, bark from hardwood trees" -- brags on moisture retention and mulching usage. I took a small sample from the top of the bag (has some perlite in it). Out of two full 8.5 oz. cups, I got just less than one cup that didn't sift thru 1/4 and 1/8 and the other cup + sifted thru the 1/8 and aluminum insect screen. Everything I sifted went thru 1/2. Granted, I didn't go very deep in the bag, but I didn't encounter any of the large pieces like in your second pic.
Sorry, Linda. I know you've really worked hard at finding the bark, so I spent some time on the phone, calling around on your behalf, and discovered that Timber Solutions on Highway 242 near 45 in Conroe has double grind pine bark in bulk for $24/yd. They said it's on sale right now; and I think I remember you mentioning the availability of a trailer, so this sounds like it could be the ticket.
I don't give up easily. I went back to SW Fertilizer to check again, and I found a bagful of Sugar Corn Pop size fir nuggets! It's Schultz's Orchid Mix! I remembered you saying to check out the orchid mixes and there it was. Problem is that it is $5.99 for an 8 qt. bag which is very cost prohibitive.
But at least I've found it and now know what it feels like to find dime-sized, gold nugget, pine bark fines!
So. Here's the pic of what's in the bag. Then we'll move on toward Conroe, cause if I'm going to make enough mix for at least 15 eBuckets, I'm gonna need to hike on up 45 with that trailer, right? And, thanks a million for helping me out!
I know you spoke at length with them in Conroe explaining just what you were looking for right? So, it's the right stuff? I could go Saturday afternoon. I'll google to see if they've got any pics online and to get directions.
I double-checked on the Supplier in Houston, and he has a location in Missouri City on S. Gessner that also has the double grind pine bark. I'm going Saturday to pick up a load.
I'll be using my eBuckets and Earthboxes (SWCs) this season. When I do get a raised veggie bed built, can I use this pine bark in it too? Just wanna know what else I can do with the excess I'll have...
I've seen lots of DGPB before, and it's usually been very good for use in container media, but I'm sure it varies from supplier to supplier. Send me a pic after you get it, and we'll figure out the best way to combine it w/other ingredients, so it will suit your purpose(s).
If you want fir bark for the gritty mix, go to the yellow pages and start calling orchid growers and businesses that cater to them - preferably large outfits that have their own greenhouses and sell supplies to hobby growers. Tell them you're making your own medium, and need fir bark in 1/8-1/4" size.
Yes, you should be able to utilize the DGPB in raised beds, too.
Yes since using this mix and the principles taught here, I find that my plants, who usually struggle from drought or heat or root rot are flourishing in the pots. It is very hard to garden in this zone, hence the screen name Hell in Zone 11(sunset). I proved this equation by making a few large batches and putting it in some large pots. The ones with the old mix, struggled to bloom and retain enough moisture, seemed choked out of O2 and it is harder to figure out what to do to make them improve. The ones in this Mix, don't seem affected by most anything, they seem to hold on to the fertilizer as well, not wash out, not sit stagnating on the bottom.
Hellnzn11 & Tapla,
Question about planting in the 5:1:1. Since the pine bark is roughly in "chip" form, it's the fines and the peat and perlite that comprise enough of a "soil" texture for the plant to send roots into and establish some anchorage in, yes?
Oh you need to direct the question to the master, I ignorantly followed a recipe, as closely as I could, it may not be exact either, but the principles he shared made good sense to my plants apparently. I defer to the Master Talpa and bow out in humility.-
Hi guys - been to the big city (Detroit) car shopping. Sorry I'm late. ;o)
"Since the pine bark is roughly in "chip" form, it's the fines and the peat and perlite that comprise enough of a "soil" texture for the plant to send roots into and establish some anchorage in, yes?"
Not really. Even large chunks of pine bark will support great growth and supply adequate anchorage. The problem with large chunks isn't related directly to texture; rather, it's related to water retention. You can grow perfectly healthy plants in a bucket of those 'boulder' size marbles, the ones about as big as a Tootsie Pop sucker, if you want to stand over it and water every 20 minutes.
Back to Linda's question. The large bark particles provide the base for a very well-aerated soil that might not have enough water retention. The fine particles are the 'balance'. Start with the large particles and add enough fine particles so you can keep up with watering ...
After I figured out that insufficient aeration and excess water retention was a limiting factor in my growing, I set about trying to figure out how to reach a favorable balance between the two. I already knew I was willing to water a little more in exchange for better growth/vitality, so it wasn't much of a leap to see that larger particle sizes were the key. From there, I factored in cost, and determining what ingredients were best suited to the role they needed to fill in each soil. Long story short, I settled on two basic mixes that were pretty flexible. By varying a few simple ingredients, you can change water retention so it suites your particular needs.
The original recipes should be usable by almost anyone, but they're just frameworks for you to build on. I was never selling a soil, or a couple of soils. I'm selling a concept - that soils that are durable and retain excellent aeration while still providing adequate water retention will make your life so much easier, will offer the best opportunity for you to produce plants growing at as close to their genetic potential as possible, and have a LOT of potential to improve your effort:reward quotient.
How do I look at the joking around? That's a really hard question to answer, because I like to joke around and trade stories/wise cracks back and forth too. Even though I'm always serious about helping people, I'm sure I come off as more serious than I actually am in 'walking around mode'. I also tend to try really hard to respect the original topic of threads. That doesn't mean I won't follow and participate as conversations morph from the original topic, but if the new topic is unrelated to the thread, and doesn't contribute anything meaningful to the thread, I try to avoid posting. Even when people ask me off topic questions on someone else's thread, I tend to be polite and offer the briefest answer possible, and point out I'm uncomfortable being off topic on someone else's thread, and usually suggest D-mail.
Some threads are less serious than others though, destined from the beginning to be short-lived. It doesn't seem to matter much if those threads dissolve into off topic chatting back & forth between parties after the subject seems to be exhausted. This thread is a little different than that, though. I think a lot of people follow this thread, and many come to it often for reference. I often wonder how frustrated they might be, having to read through the conversational posts to get to the information they're looking for? Actually, I've only asked a couple of times on my own threads for people to stick a little closer to the topic, but OTHER posters have expressed their dismay about off topic posting several times, which is one of the reasons I think people are regularly following this post.
So how do I decide what's appropriate when it comes to posting? I can only say that I try to ask myself these questions: What is the nature of the thread? Is my offering on topic? Will it be informative, or, does it have the potential to interest more than 1 or 2 people involved in the conversation, and is that conversation on topic.
Many of you guys have first hand experience, even apart from my threads at Dave's, re. how far I'll go to help to anyone who asks for it or needs it. Remaining on topic could easily be looked at as being respectful of that effort, and of anyone who might be looking through the information in these posts next week/month/year. It's all good, guys. I always appreciate your participation and enthusiasm - always. ;o)
Makes sense, many people come here to get the info and it is a little scientific in the beginning so I guess off topic for this long of a thread, would be hard to decipher where info starts and the banter being more of a nuisance. I am a banter type person all in all, because I come here for friendship as much as info, but I do get why you are that way about the topic. It's been helpful. Thanks.
We might as well go off topic and talk about this if anyone wants to. I'm curious how others feel about OT posts. It's not as easy as it sounds, and I understand that. For instance, my comment that 'I was in DET car shopping, so couldn't respond to the posts' was clearly off topic. I followed that with an on topic reply to Linda, then launched into another discussion that is probably off topic, though in the end it will hopefully be a benefit to the thread. I have a lot of friends on the forums that I've helped over the years, and we all enjoy chatting with each other. For many, the very natural thing to do would be to ask if we bought a car, or what kind of car(s) we were considering, much like a real time conversation between pals would go. Maybe the answer is to keep the pleasant chatter (which I really enjoy, BTW) short, and mix it in with other on topic offerings. I'm not just talking about this thread now - more like how to satisfy our need to network beyond the OT and still be respectful of the OP's efforts and others following the thread.
I often take that approach when I see people joining someone else's thread who need encouragement or guidance. I try to offer help when I can, but I do it in such a way that the comments are pertinent to the thread.
Just recently, I've seen comments by folks with dual memberships on two different threads at GW, mentioning the fact that here at Dave's, threads very often, to the point where you might even be able to say 'usually', break down into chatter between two to several people that has nothing to do with the OT. I don't know how others deal with that, but I usually just stop watching the thread because it's almost like listening in to someone else's phone conversation. I'm sure I miss some opportunities to offer on topic comments or help, but ...
I don't want anyone to feel bad or like they're not more than welcome, so let's talk this out, & then we can get back to soils. If there are no comments, we can just get back to soils. ;o)
I just found that my local source for mulches and soils seems to have an appropriate fir bark on their product list. I'm hopping in my car now to go and see what it really looks like. Check it out. It's called 1/4 Minus Fir Bark.
The smallest particles in the smallest size LECA are still about 3X larger than ideal for the gritty mic, Susan.
If you're screening the bark, save what passes through 1/4 but what doesn't pass through 1/8 for the gritty mix. The fines that pass through 1/8 can be added to the 5:1:1 mix, which is what I use for all my veggies and the pretty display containers I have scattered through the gardens & on the decks. Waste not - want not. ;o)
tapla wrote:The smallest particles in the smallest size LECA are still about 3X larger than ideal for the gritty mic, Susan.
If you're screening the bark, save what passes through 1/4 but what doesn't pass through 1/8 for the gritty mix. The fines that pass through 1/8 can be added to the 5:1:1 mix, which is what I use for all my veggies and the pretty display containers I have scattered through the gardens & on the decks. Waste not - want not. ;o)
Thanks, Al. I saw some of what I think is LECA at a local building/garden supply place today and you are absolutely right. I had no idea from the original picture I saw of the stuff that it was so huge...kinda like marbles... Scratch that idea.
Okay, so now I need to go and source some 1/8" screen...
This is like a treasure hunt, and it is interesting visiting all my previous haunts looking for new stuff and seeing what they do and don't have that just hasn't registered before. At the same place I found the LECA, I did pick up a bag of pumice that I would never have noticed before. Also a new fixture for putting a t-5 grow light into... Shop shop shop... The rains will start tomorrow and I will have all sorts of indoor projects...
Linda - hopefully the double grind I put you on to won't need screening, but I would say 'ideal' for the 5:1:1 mix (in containers) would be everything that passes through 3/8 mesh. See picture from 9/11 upthread.
Susan - you're very welcome. Best luck! ;o)
I found 1/8" wire, pigeon grit, and I'm probably set to rock and roll, but now I'm going to have to go back to the beginning and see what to do with everything. I picked up two new Semps while I was out, so they will be my first victims...:-))))
This is a lot to read and very informative; I am learning a lot. I belive that Al (Tapla) is simply trying to pass along information and insight in a helpful spirit. There will always be some folks who take offense as though the knowledgeable one were a braggart. We need to realize as gardeners that we share a common passion and that Al is saving us time and trouble by sharing what he has learned.
That said, I have a question or two: In the event that bagged potting soils are the only choice available at the moment, is orchid soil the best bet? I have stopped buying any bagged potting soil except orchid soil available at Wal-mart and Lowe's. I pot everything in it except cacti and succulents. For those, I use cactus soil, also found at Wal-mart.
What is the usefulness of growing things in peat at all? I start many things in Jiffy peat pellets and find them great for getting seeds and little plants started. I will even keep such starts in peat for a long time until the plants are overgrown and must be potted up. Then the young plants usually go into orchid soil.
This year, I want to take the steps that Al has outlined to make my own soil based on the science that he has provided. Thanks so much!
Peat is light to ship, plentiful, inexpensive enough to present a greater potential for profit for potting media (soil) packagers, and many/most people are willing to pay for the convenience of not having to go to the effort of making their own soil. As you probably already know, I have found that with only a little sweat equity, you can make a much superior soil for less.
I think that to make a judgement about whether orchid soil is better or best, we would need to know a little about it's composition, primarily the size of the particles and their physical characteristics. I think it's important to understand that what this thread emphasizes isn't so much the particular soil recipes; rather, I wanted to point to the fact that well-aerated and free-draining soils that have, inherent, the ability to retain those properties for the intended life of the planting, offer much greater opportunity for plants to grow to their genetic potential within the limiting effects of other cultural factors. The soil recipes are just good examples of how you can implement that concept.
For several reasons, soils that support little or no perched water, yet still offer good water retention, will be more productive AND easier to grow in, offering a much wider margin for grower error in both the watering and fertilizing depts.
I use the 5:1:1 soil, pine bark:peat:perlite for all my veggies, mixed floral display containers, and the short tern plantings (1-2 years in the same container). For ALL my trees/shrubs, houseplants (including cacti and succulents) - all the long term plantings I think will be in the same soil for 2 years +, I use the very stable 'gritty mix' seen in the picture.
Fafard makes a couple of good mixes if you can find a dealer that will get them for you. Their #51L and #3 mixes are good, with the #51L getting the nod over #3 because it is slightly more porous. I know it's sometimes difficult to locate the right size bark, but once you get a supplier located, making your own is very easy. I dump a bag (2 cu ft) of bark and about 3-4 gallons each of peat & perlite on a tarp, along with the lime & anything else I might be adding. I then mix with the flat side of a garden rake (so I don't tear the tarp) before I pull on the corners of the corners of the tarp so the ingredients are all thoroughly folded/mixed together. If you don't count the 5 minutes it takes to screen the peat to break up any clumps & get the big sticks out, I can have a 3-4 cu ft batch made in 15 minutes. Clean-up is easy because everything stays on the tarp. I use a plastic dust pan to scoop the soil back into sturdy bags I keep (like 50 lb dog food bags) for that purpose, or scoop it back into the pine bark bags for future use.
I put the bark down first & moisten, then pour the peat on top, then the perlite and moisten the perlite. After it's folded together & sits for a few minutes, the hydrophobic tendency of the peat is eliminated as moisture from the bark & perlite diffuses into the peat particles.
I'm getting ready this spring to repot all of my houseplants with Al's soil mix (the gritty mix). Just one little question that I haven't been able to find the answer for reading this thread, which is probably because my brain can't keep track and is in overload! What is Turface and where can one buy it?
Turface is calcined (fired at a high temperature) clay. The special clay is heated until the tiny particles fuse, so they are like hard little ceramic sponges. After screening, their large size allows water to flow through the particles, leaving large air pores between the particles, with water trapped INSIDE the particles for plants to use. The result is lots of aeration, no perched water, and good water retention.
In the picture, you can see Turface on the left and crushed granite on the right. Pay no attention to the soil on the top. It's a handful of soil from my raised beds & too fine (water-retentive) to be suitable for use in containers.
Very good Timmijo! You definitely 'got it'. The only thing I would add to what you said is that drainage layers don't eliminate PWTs, they only serve to raise them in the pot. E.g., if you have a soil that supports 3" of perched water in a 4" deep pot, after a thorough watering, 75% of the soil will remain completely saturated. If you put that soil on top of a 1" deep 'drainage' layer, it will leave you with the entire soil mass saturated.
Getting ready to screen the pine bark fines for my eBuckets! I am sooooooooo excited! Gilraen already screened and did her raised beds, and she's happy, too!
Question: I'm about to plant potatoes in my 20-gallon SmartPots and old washing machine tubs. Can I use the 5:1:1 mix or should I go with regular garden soil in those containers for growing potatoes? Last time I started with 8" of aged compost, and hilled up as the potatoes grew to the top of the containers. Then, I wrapped the containers with plastic poultry wire, and continued hilling with leaves. Had a nice little harvest.
Should I use any of your mixes for growing potatoes in containers? They like a loose, well-draining growing medium...
Lol - I don't know about that, Steve. I have a thread over at GW with almost 1,800 posts to it. ;o) Thanks though. I hope all is well with you! Spring's just around the corner.
Linda! The pictures didn't come through to my phone. ;-( Chime, but no pics.
If the bumper crop of sweet potatoes I had from the ornamental varieties of sweet potato vine is any indication, the 5:1:1 mix should do a bang-up job for you. Half way through the summer, the containers I had the vines in started showing soil well above the pot rims. It was really hard to water because the soil was much higher than the rims. I knew it had to be sweet potatoes ... and it was. ;o) I found the bottom of the containers loaded with them after the frost came. Too bad they're no good for eatin'! TTYS
I've spent hours reading through the first two threads, dating back to 2007, and I think I've got a basic understanding of everything. It's a lot of information, but the discussion (questions and answers) really do help clarify most everything. After posting my question about Turface (a half-dozen posts above this one), I found the answer in the second thread, but I hadn't read that far at the time. Sorry to have asked you to repeat yourself, Al.
So now, I just have to wait until better weather to get the materials and repot my dozens of houseplants. I found a source for pine fines right off, at a local mulch dealer. They have "Pine Bark", described as "made from the bark of a pine tree (duh!) with a particle size of 3/4" minus." So, that means I screen it to remove the smaller particles and dust, right? When I called them, they said it had been "aged" but not composted. They use it in their "perennial mix" soil containing "pine fines, sphagnum moss, and hardwood fines".
If I understand correctly, I could use small grade haydite to substitute for Turface, if I can't find the latter, but I would have to smash and screen it to get it down to size. I think I can find turkey grit though.
Sphagnum peat moss is no problem. Looking forward to spreading out the tarp and getting started mixing!
Here's the picture of the pine bark fines we found. I'm really, really, really happy to have found a source, even if I do have to screen it. Nothing will go to waste, since I can throw the larger chunks into the raised beds I'll build for the fall! I'll have a good bit of "dust to nickel-size" material to work with for my eBuckets. I bought fresh MG Potting Mix as the peat component and I have the course perlite. I also found the MG Liquid Plant Food in the 3-1-2 ratio (it's 12-4-8)!
I think I'm in business! Can't wait to see the results. It's been a long time coming!
P.S. Could I run the larger pieces through a wood chipper if I ever needed more "fines"?
Thanks for the affirmation that the lengthy discussions truly are sometimes necessary for clarification. Al worked with me in discussions for over 3 months. So much came from the discussions, and I finally believe I have an understanding of his process.
At first, I wanted no part of the "technical" jargon, but, the more that was revealed, the more I was drawn into gaining a complete understanding of the discussion. I, too, have gone back to reread the posts for clarification. I'm glad they were there for reference.
Al is a blessing to this gardening site, and I am happy to be among his "cheerleaders!"
P.S. I was answering you about what Turface is, immediately after you posted. I had half a reply typed up on my itty-bitty cellphone, then hit the wrong button and lost it all. I got totally aggravated...sorry you had to plow through so much of the discussion to find that answer.
How about some of us "plow through so much of the discussion" and pull out some sort of "glossary of terms" to be put into a sticky at the beginning of this Forum? That way, people coming in at the end wouldn't have to dig so hard for the answers that already exist?
Or, we could pull out the major terminology and include the link to where Al explains the term.
It's actually great fun to respond to a question from a neighbor, as to why their potted plants are not doing well, and be able to say: Most likely it's your perched water problem: soil which retains appreciable amounts of 'perched water' and remain soggy after it’s saturated.
Jeez! Just when I thought I had it down... QUESTION!!! I thought screening the pine fines was to get OUT the dust and smaller particles, but the way I'm reading the latest posts is that the stuff that drops through the screen is what you use... right? To make sure, the screen used is like hardware cloth, correct? Boy, I'm getting confused all over again. I know Al posted photos, but I am still unsure of the size of the pine fine pieces.
While I'm asking...Al's basic soil mixes have pine bark fines, peat, perlite, lime or dolomite, and CRF + micro-nutrients. His "long-term" mix for woody plants including houseplants is pine fines, Turface (or haydite, perlite, or lava rock 1/8"), BUT ALSO crushed granite (or turkey grit), a little gypsum, the CRF and micro-nutrients. But NO PEAT. Am I understanding this correctly? What I want to do is repot my houseplants with the second mix, but just wanted to make sure there is NO peat in the recipe.
I'm using Al's 5:1:1 SOIL mix for container veggies. PBFs:Peat:Perlite. It will provide good aeration plus drainage for my veggies. Al has suggested I go with a 2:1:1 or a 3:1:1 mix which utilizes more peat (in my case, MG Potting Mix) ratio so I will have more of a wicking action in my self-watering units that have a built-in reservoir. All the 5:1:1 mixes contain a peat component. And, all the 5:1:1 mixes used the PBFs that are anywhere from "dust to nickel-size". Whatever drops through 3/8" hardware cloth is used in the 5:1:1 mix.
The lime and calcium are added to the 5:1:1 mix to supplement veggies that require these additives, more specifically, tomatoes.
Then there is the second "GRITTY Mix" . This recipe for planting all the other stuff (it's Al's "long-term" mix for woody plants including houseplants). This includes PBFs, Turface (or haydite, perlite, or lava rock 1/8"), crushed granite (or turkey grit), a little gypsum, the CRF and micro-nutrients. But NO PEAT.
Hope this helps.
P.S. I think there's actually a 3rd mix or a variation of the Gritty Mix. But, I'm not using any mix other than the SOIL mix, so I can't really speak to the Gritty mix, except I know it doesn't have the peat.
Here's the link to the original site where all FOUR recipes ( I was short by one!) are found toward the top of the thread (whew!). If the link doesn't activate itself, just copy it and paste it directly in your browser to go there...
Hoosier - You don't have to wait until better weather to GATHER the ingredients. I make sure I always have on hand what I need to make my years supply of soil (plus I'm always sharing with others - which means I buy Turface & bark by the pallet. ;o) That way there's never any last minute scrambling to find the 'last ingredient'.
Please note there are multiple discussions going on - primarily that we are going back & forth, discussing two different soils with different ingredients, so it's easy to get confused. ;o) If you're making the gritty mix & using pine bark, you can use what does pass through a 3/8" screen but what doesn't pass through 1/8". I see you're talking about Haydite & Turface, which usually don't go in the 5:1:1 mix, and also about peat, which is absent from the gritty mix.
Finding Haydite in a good size has always been problematic for me. It's always too big. Actually though, Haydite holds considerably less water than Turface, so it would probably be a more suitable sub for the granite - if you can find a suitable size.
Hey, Linda! - It DOES look like you're in business! The bark has a lot of large particles, so running it through a chipper before you start would be great - if you have access to one. How about posting a picture of the bark you settle on before you add in the peat? I can probably help you with a guess as to how much peat to add, based on the bark particle size.
Thanks to everyone for being so kind & for all the enthusiasm. If it wasn't for you're enthusiasm, I'd be tired of covering the same material, but I find it catching. I love being around plant people as much as I enjoy tending my plants, so all the friendly people can take a bow for making this thread so much fun, and such a pleasant place to hang.
I've become so comfortable talking about soils, and it's made such a difference in so many peoples growing skill set, that I'm starting to get asked more & more to speak to various groups - most often by far about soils, but sometimes about pruning, bonsai, propagation, fertilizing, tending houseplants ... Where I probably averaged a talk per month for the last several years, I find that now I'm getting busier. I already have 4 commitments in the next two months, and 3 others between then & August.
How interesting can soil be? The last talk I gave was supposed to last an hour. I ran over by 20 minutes & not one person had left yet (one might have got up to leave, if she was awake). ;o) Even after I ran over 20 minutes, there were still people gathered around asking questions as I was picking up my stuff - for about another half hour. It doesn't trip everyone's trigger, but when I stand in front pf people, I see that light go on - again and again. People are struck suddenly by what I'm saying about the PWT and soggy soils. I've heard "Oh! NOW I get it!" more times than I can count - here on the forums, too. It's soo much fun to be the good news provider! Lol Now YOU guys have the goods & can help others see how/why these highly aerated soils work so well - but make sure to be straight & tell them they have to scout out the ingredients and make the soil - then water a little more often. ;-)
John - Gritty mix for houseplants =
1 part screened pine or fir bark (1/8-1/4 if fir - 1/8 - 3/8 if pine)
1 part screened Turface MVP or Allsport (over insect screen)
1 part crushed granite (Gran-I-Grit in grower size, #2 cherrystone, other)
Maybe gypsum (depending on what you use for a fertilizer - I choose Foliage-Pro 9-3-6)
I screen the dust out of the granite over insect screen, even though it's pre-screened.
Thanks for the comeback! I'm gonna go ahead and make a 3/8" screen, and use whatever falls though (that's the right grid, right, 3/8"). If you look vertically along the far RIGHT edge of the picture, you'll see the particle sizes I'm hoping to capture (give or take those 3-4 chunky pieces); from dust to no larger than nickel size. Nickel size may require a larger screen, huh?
Or should I shoot for no larger than dime size? Which screen for dime? Which screen for nickel?
Added Note: I agree that Al should check into marketing his soil mixes. Here in central Indiana, we have a retired extension agent, kind of a folksy character nicknamed "Dr. Dirt", who makes a killing with a newspaper column, speaking engagements including radio spots, special appearances at the Indiana State Fair, AND as the creator of a special blend of his soil mix, "Dr. Dirt's Premium Growing Mix". It contains pine fines, sphagnum peat, and hardwood fines. It's mixed, bagged, and promoted by a local mulch business, with great success.
I think Al's mixes would be a great improvement, and a much needed choice for gardeners!
Linda - nickle size pine bark is fine for the 5:1:1 mix - no problem - as long as there are lots of finer particles, too.
Hoosier - hdwe cloth comes in lots of sizes. I have two sets of screens (different sizes), & I think they are insect screen, 1/8, 1/4, 3/8, 1/2' sizes. See picture.
No dust in the gritty is the best course.
Most people use a calcined DE (diatomaceous earth) product if they can't find Turface. Perlite doesn't retain much water, so would be better as a replacement for the granite.
Each of the ingredients in the gritty mic are selected for a reason, and they are the best at what they do, according to what I've been able to come up with. You can get Turface at Harrell's Inc. in Whitestown (800) 966-1987, Cisco in Indy (800) 888-2986, Tenbarge Seed Company in Haubstadt (812) 768-6157, John Deere Landscapes on Castlegate Dr. in Indy (317) 576-1888 ... that should be enough to get you on the right track. Ask for Turface MVP or Allsport.
The Foliage-Pro 9-3-6 has ALL 12 essential nutrients (including Ca & Mg, commonly missing from soluble fertilizers) plants get from the soil, in the right NPK % AND in a favorable ratio to each other (the same ratio in which plants actually USE the nutrients). It doesn't get any more foolproof than that.
You can use the CRFs if you choose, but you pretty much give up control over your fertilizing program. I rarely use them.
Thanks very much for the kind thoughts - a nice compliment. ;o)
Many thanks for the clarification info. Looks like I can find Turface easily in this area.
(I was mixed up about the perlite. From what I understand now, the Turface in the gritty mix does the same job as the peat in the basic soil mix and is the water-holding material. The crushed granite in the gritty mix takes the place of the perlite in the basic mix and is the drainage/aeration material.)
But, just one more clarification about fertilizing:
If I don't use a time-release fertilizer, what strength and frequency do you recommend using the Foliage-Pro 9-3-6, which if I understand correctly, you apply with every watering? I would imagine the instructions give the dosage if using with every watering, so perhaps I've answered my own question!
Edited to ask: Is Redland Supply in Florida still the best source for buying Dyna-Gro's Foliage-Pro liquid 9-3-6?
Many thanks for the clarification info. Looks like I can find Turface easily in this area.
(I was mixed up about the perlite. From what I understand now, the Turface in the gritty mix does the same job as the peat in the basic soil mix and is the water-holding material. The crushed granite in the gritty mix takes the place of the perlite in the basic mix and is the drainage/aeration material.)
Close enough that it doesn't need clarification. You got it.
If I don't use a time-release fertilizer, what strength and frequency do you recommend using the Foliage-Pro 9-3-6, which if I understand correctly, you apply with every watering? I would imagine the instructions give the dosage if using with every watering, so perhaps I've answered my own question!
I fertilize with every watering in the winter, because I over-winter only about 100 plants indoors. In the summer with 300+ containers to attend to and no fertilizer injection system, it's not practical for me to fertilize at every watering, so I try to fertilize every week or two, depending on how robustly everything is growing. I pretty much use leaf color as my guide to when plants actually NEED fertilizer, but after a while, you get pretty good at anticipating your plants nutrient needs and supplying them before they show a need. Fortunately, you have a much wider margin for error in both fertilizing AND watering when using fast (draining) soils that allow you to flush the soil when you water. I think the 'recommended' dose on the 9-3-6 label is too light in most cases. I'm able to fertilize at 4-5 teaspoons in 2-1/2 gallons of water weekly when plants are growing well and it seems to be just right. If it's cool or hot, I'll either increase the interval between fertilizing or decrease the dose.
I don't really know where the best place to get the FP 9-3-6 is. I either pick it up in CHI where I buy bark for the gritty mix (no freight), or just shop around online for the best buy.
Gymgirl/Gilraen: Your new theme song. Pay particular attention to the chorus!
When repotting into any soil, you should bare root in one or two repotting sessions a year apart. That is, some plants can be bare rooted & all soil removed in one session, others should have half the old soil removed one year & the rest in the subsequent year.
CHI = Chicago! Yeah! Do you buy it at a supply place there ...well, obviously... but is it retail, open to the public? Where please? I have a daughter in Chicago, and we go there quite a few times a year to visit. Thanks!
I buy the fine fir bark on the page I linked to for use in my bonsai soils/the gritty mix. I see the price just went up to $20 for 3 cu ft bag, prescreened 1/8-1/4". It's actually NW of CHI in Dundee. I was getting it for $15 if I bought 20 bags. I'm guessing I'll have to wheedle to get him down to $17/20 bags. ;o)
Thank you for making my day. Unfortunately, there was exactly ONE thing that broke my stride on this long weekend I took to start my potting -- I strained my back Friday and couldn't move for the two days without almost unbearable pain.
Bummer! I took enough painkillers to down a whale. And nada. But, ya'll know I'm determined. I sat on the floor and managed to sift one bucket of PBfines. And this evening I planted one seedling in an eBucket...
"I've got to keep on movin'!!"
Al, I sent you pics of my sifted Pbfines so you could tell me whether to go 2:1:1 or 3:1:1 in the eBuckets, but you didn't see them. So I did a 3:1:1. It sure seems to soak up a lot of water before it drains! I was getting worried, thinking I was filling the whole bucket with water! We'll see in about a week.
I've taken to buying medium pine bark "mulch" from a good nursery, $8 / 2 cubic feet.
What Home Depot sells for "bark mulch" is really junky, but half the price or less.
I can screen the better mulch with 1/2" & 1/4" hardware cloth and get usable chunks. I THOUGHT I had a fast-draining mix for seeedlings, but when I potted them up, I saw that the first batch had too many fines - there was no visible air space, and it was fairly soggy.
That's why I switched from 1/2 & 1/2 fine and medium mulch. The medium grade has fewer fines.
What passes through the 1/4" screen is good for amending heavy clay soil in raised beds.
What won't pass through the 1/2" screen at all I use for literal mulch on RBs.
PP - it's not the best price, but it's not highway robbery, either. There is a place between Toledo & Sandusky that sells fine fir bark, but I can't seem to find where I saved the info. It's a wholesale/retail outfit that sells all kinds of forest products. I'm thinking your 'flower supply' outfit almost certainly buys their product from the entity I'm referring to. I'll see if I can find out for you, but give me a couple of days. I owe a friend from Ann Arbor, MI an email, but he may be away for the weekend or about to leave.
I'm low on fir bark now, but I'm heading to CHI in Aug. I last paid $15/3 cu ft, but I see the regular price is up by $3 to $20, so I expect I'll probably pay $17 or $18 if I buy 20 bags or more, but that price is for 3 cu ft bags.
At another forum site, I wrote the following because someone had asked if Scott's Premium Soil was a 'good' choice. You may find it of interest.
Is Soil X a Good Soil?
I think any discussion on this topic must largely center around the word "GOOD", and we can broaden the term 'good' so it also includes 'quality' or 'suitable', as in 'a quality or suitable soil'.
How do we determine if soil A or soil B is a good soil? and before we do that, we'd better decide if we are going to look at it from the plant's perspective or from the grower's perspective, because often there is a considerable amount of conflict to be found in the overlap - so much so that one can often be mutually exclusive of the other.
We know that grower A isn't happy unless he is squeezing every bit of potential from his plants, and grower Z isn't happy unless he can water his plants before leaving on a 2-week jaunt and still have a weeks worth of not having to water when he returns. Everyone else is somewhere between A and Z; with B, D, F, H, J, L, N, P, R, T, V, X, and Y either classically ignorant (it just means they're not aware there is a difference) or they understand but don't care.
I said all that to illustrate the futility in trying to establish any sort of standard as to what makes a good soil from the grower's perspective; but lets change our focus from the pointless to the possible.
We're only interested in the comparative degrees of good and better here. It would be presumptive to label any soil "best". 'Best I've found' or 'best I've used' CAN be useful for comparative purposes, but let's tackle 'good', then move on to 'better', and finally see what we can do about qualifying these descriptors so they can apply to all growers.
I would like to think that everyone would prefer to use a soil that can be described as 'good' from the plant's perspective. How do we determine what a plant wants? Surprisingly, we can use %s established by truly scientific studies that are widely accepted in the greenhouse and nursery trades to determine if a soil is good or not good - from the plant's perspective. Rather than use confusing numbers that mean nothing to the hobby grower, I can suggest that our standard for a good soil should be, at a minimum, that you can water that soil properly. That means, that at any time during the growth cycle, you can water your plantings to beyond the point of saturation (so excess water is draining from the pot) without the fear of root rot or compromised root function or metabolism due to (take your pick) too much water or too little air in the root zone.
I think it's very reasonable to withhold the comparative basic descriptor, 'GOOD', from soils that can't be watered properly without compromising root function, or worse. I also think anyone wishing to make the case from the plant's perspective that a soil that can't be watered to beyond saturation w/o compromising root health can be called 'good', is fighting UP logic hill.
So I contend that 'good' soils are soils we can water correctly, that is we can flush the soil when we water, without concern for compromising root health/function/metabolism/. If you ask yourself, "Can I water correctly if I use this soil?" and the answer is 'NO' ... it's not a good soil ... for the reasons stated above.
Can you water correctly using most of the bagged soils readily available? 'NO' I don't think I need to point to a conclusion.
What about 'BETTER'? Can we determine what might make a better soil? Yes, we can. If we start with a soil that meets the minimum standard of 'good', and improve either the physical and/or chemical properties of that soil, or make it last longer, then we have 'better'. Even if we cannot agree on how low we wish to set the bar for what constitutes 'good', we should be able to agree that any soil that reduces excess water retention, increases aeration, ensures increased potential for optimal root health, and lasts longer than soils that only meet some one's individual (and arbitrary) standard of 'good', is a 'better' soil.
All houseplants, unless grown from seed, have the genetic potential to be beautiful specimens. It's easy to say, and easy to see the absolute truth in the idea that if you give a plant everything it wants it will flourish and grow; after all, plants are programmed to grow just that way. Our growing skills are defined by our ability to give plants what they want. The better we are at it, the better our plants will grow. But we all know it's not that easy. Lifetimes are spent in careful study trying to determine just exactly what it is that plants want, to make them grow best.
Since this is a soil discussion, let's see what the plant wants from its soil. The plant wants a soil that contains in available form all the essential nutrients, in the ratio in at which the plant uses them, at a concentration high enough to prevent deficiencies yet low enough to make it easy to take up water (and the nutrients dissolved in the water). First and foremost, the plant wants a container soil that is evenly damp, not wet. Giving a plant what it wants, to flourish and grow, doesn't include a soil that is half soggy for a week before aeration returns to the entire soil mass, even if you only water in small sips. Plants might do 'ok' in some soils, but to actually flourish, like they are genetically programmed to do, they would need to be unencumbered by wet, soggy soils.
We become better growers by improving our ability to reduce the effects of or eliminate limiting factors, by clearing out those things that stand in the way of the plant reaching its genetic potential. Even if we are able to make every other factor that influences plant growth absolutely perfect, it could not make up for a substandard soil. For a plant to grow to its potential, every factor has to be perfect, including the soil. We'll never manage it, but the good news is that as we get closer, our plants will get better and better. It's that one little factor that we willingly or unwittingly overlook that limits us in our ability and our plants in their potential.
A 2-bit plant in a $10 soil has a future full of potential, where a $10 plant in a 2-bit soil has only a future filled with limitations. ~ Al
I primarily grow orchids, but came to this site in search of some information that would help me grow healthier and more productive tomatoes. What a fantastic resource you have provided here...you are to be commended!
Light bulbs were popping off for me all over this thread, as many of your concepts have application for growing orchids, too. Most orchids are epiphitic (grow with roots in the air)...we only grow them in pots for OUR convenience. Discussions of potting medias is always a hot topic on orchid forums. Everyone is in search of the "best". But one key and often overlooked element in providing the right culture is "what kind of waterer are you?" I do all my growing from a wheelchair, so frequent watering indoors is sometimes a challenge (unless the plants like to actually have wet feet.)
Frequent watering for tomatoes in summer is not such a big deal, so I am raring to go with your approach! I have already discussed your recipe with my DH (I had to warn him that my tomato pots were going to be dumped out...again), and even with a quick overview, your suggestions made sense to him, too.
I sure wish you grew orchids! There are a lot of people who could benefit from your knowledge.
Have you ever evaluated MSU fertilizer (yes, from Michigan State)? It's been specifically formulated for orchids and uses non-urea nitrogen sources; I'm wondering if it is similar to Foliage Pro 9-3-6.
Also, have you heard of Orchiata bark? It comes in a variety of sizes and is supposed to have 2-3 times the useful life over other barks. I have started using it with many of my orchids, and the results so far are extremely favorable.
BTW, if anyone is interested, not all "orchid bark" is the same. My experience with most packaged barks is that they begin to decompose in a matter of months and turn into mud...yuk!
Do you have any specific recommendations for your soil and tomatoes? I get really tall plants, but not many tomatoes. And I fight with blight and/or powdery mildew.
I also realized that the perched water issue might be why I haven't been able to grow shallots in pots. I will try again this year!
Thanks again for being so generous with your time and knowledge!
Hi, Katherine. We're almost neighbors, eh? ;^) First, let me thank you for the kind words and the compliments. I really appreciate your making the effort. I'll probably seem to skip through topics like a kid through spring puddles, but it's because I'm following your post and commenting as I read. I do grow a few hardy terrestrial orchids in the gritty mix, and they do exceptionally well. Great looking foliage & excellent bloom quality and quantity. I've had a number of others contact me to say they use it for non terrestrials too, but not being well versed in orchid nomenclature,I can't be helpful in sharing what they were growing. Sorry about that part, but its would seem worth some experimentation?
MSUs's orchid fertilizers are similar to Foliage-Pro in that they don't derive their N from urea, and they relegate P levels to something more realistic than 1:1:1 ratio fertilizers like 20-20-20 solubles or 14-14-14/15-15-15 controlled release. These fertilizers supply excess amounts of P for all plants, and the 'bloom booster' fertilizers are worse offenders, some of them being so far out of line for containerized plants as to be ridiculous. 10-52-10 (a commonly found 'bloom booster' blend), after applying the the required factoring to determine the actual P supplied, (X.43 of what's reported) supplies almost 14X as much P as the plant can use in relation to N. That's ridiculous to the point a case could easily be made it's irresponsible. MSU's fertilizers also contain a full compliment of all nutrients, including Ca/Mg, and in favorable ratios. I would have no problem using it if I couldn't get the FP 9-3-6.
That I haven't used it doesn't mean much. The science involved with how it's made and what it's made from, as well as what it provides, is quite clear - you don't need to be a bus driver to understand the wheels go round & round. ;-)
I'm familiar with P radiata, which is the tree the Orchiata brand bark comes from. Lignin is what makes trees stiff & woody, and suberin is a lipid. Both are bio-compounds shown as having extremely difficult hydrocarbon chains for microorganisms to cleave, which is what makes conifer extremely difficult for soil biota to break down. Whether it is in FACT has 2-3 times the useful life of other pine/fir/redwood bark products, or if they are referring to hardwood bark products that contain only fractions of these products compared to conifer barks is a question that would need clarification before I would take the claim at face value as being superior to ALL bark products. I just don't know and retain some degree of skepticism about the statement. It may even be a moot point because I've NEVER seen the gritty mix with for or pine bark break down before it was well past being prudent about repotting due to root congestion. IOW - why pay for a product purported to last for 10 years when the state of root congestion might require repotting at 2-3 year intervals?
Tomatoes: For soils I really like the 5:1:1 mix. I get loaded plants to 8' tall in 18 gallon tubs. I use a 3:1:2 RATIO (different than NPK %s) until the vines are 5' or so, then I cut the fertilizer in half & supplement with some additional K, in the form of ProTeKt 0-0-3. It works great. I don't have a problem with spraying my plants with Daconil, so I use that prophylactically & I never seem to be troubled with early/late blights, PM, or anthracnose (gray mold).
I use partially composted pine bark fines (usually) in the 5:1:1 mix when I can find it. If I can't, I use fresh/ uncomposted bark. I've never gone more than 3 years between repots for any of my plants due to root congestion that was obviously affecting growth and vitality by that time. What you may have witnessed turning to mud were other soil ingredients? Also, organic fertilizers can be counted on to hasten soil structure by promoting larger populations of soil biota. I look at that fact as a disadvantage and use soluble fertilizers like the FP, but the MSU fertilizer would be similar along those lines. You don't need a thriving microherd in containers to raise perfectly healthy plants, and courting their populations often proves to be an exercise in futility.
You should be able to grow onions, garlic, shallots ... in pots once you get that PWT under control. Partially burying your containers (just so the drain holes are covered) or using a wick can also be helpful. Tilting your containers on a 45* angle with a drain hole at the lowest pot (until pots/containers stop draining, will make a BIG difference in how much residual PW remains in the soil.
You're welcome ... and thanks again for the kind words.
NPK % tell you how much Nitrogen (N), Phosphorous (P), and Potassium (K) are in the fertilizer by weight. The fertilizer RATIO is much more important than the NPK %s, and describes the presence of the 3 elements in relation to each other. For example, Miracle-Gro makes 24-8-16 in a granular soluble fertilizer. Those 3 numbers are the % of NPK in the product. They also make 12-4-8 in a liquid fertilizer (yellow jug). Both fertilizers are 3:1:2 RATIO fertilizers. For every 3 parts of N, there are 1 part of P and 2 parts of K, thus the 3:1:2 ratio. It's a little like reducing fractions.
I use another 3:1:2 ratio fertilizer, Foliage-Pro 9-3-6. If you reduce the NPK %s to their lowest whole number form by dividing by 3, that too is a 3:1:2 ratio.
All plants use the same elements, in surprisingly close to the same ratio. They use abut 6X as much N as P, and about 3/5 as much K as N, so it's very difficult to build a solid case for using 1:1:1 ratio fertilizers like the popular 20-20-20 or 14-14-14 controlled release. 1:1:1 ratio fertilizers supply more than 2.5X the P plants want or can use, and the "bloom booster" fertilizers are an extremely poor choice for containerized plants because P they supply in great excess is usually detrimental. Remember, anything dissolved in the soil solution that is not needed has the potential to be limiting.
Unless we're intentionally using fertilizer in a way that limits growth, the perfect goal would be to ensure that all the nutrients plants normally take from the soil are present in the soil and available for uptake at all times, in the same ratio at which the plant uses the nutrients, and at a level concentrated enough that it ensures no deficiencies yet low enough it ensures the plant can easily take up water and the nutrients dissolved in the water. As hobby growers, the closest we can come to that would be by using a fertilizer that has all the essential nutrients in a 3:1:2 ratio.
MG 24-8-16 and 12-4-8 have almost all the essential nutrients in a favorable ratio, but they lack Ca & Mg. This isn't usually an issue if you're using a commercially prepared soil because it will almost certainly have been pH adjusted with dolomitic lime, which raises pH ans supplies the missing Ca/Mg. If you make your own soils, you need to add the lime or supply the Ca/Mg by using other amendments, usually gypsum (CaSO4) and Epsom salts (MgSO4) ... but now I've drifted well beyond the scope of your question.
I haven't been around the forums much this last week. Our weather went from regular MI winter weather to two weeks of really warm weather, including the last week in the upper 70s and 80s. I have well over 100 deciduous bonsai to repot, and they're ALL showing significant bud movement, so I took the week off. I've been working 12-15 hours repotting every day since Fri, trying to keep ahead of the trees. The forecast is for at least another week of unseasonably warm temps, too!
tapla wrote:FWIW - hardwood bark isn't appropriate as a significant fraction of container media.
Could you elaborate on why hardwood bark isn't appropriate? I have found "Premium Hardwood Fines" at Lowes for $4.16 for 2 cu ft.
I've also found "Soil Conditioner 100% composted Pine Bark" at English Gardens at $9.99 per 40 dry quart bag. It seems like its a lot more expensive (it they are the same thing). I have used this product in my blueberry beds. Had half a bag of it left from last year and just made a double small batch of the 5:1:1 for my shallots. It seemed a bit more decomposed than I expected...maybe it broke down a lot since last year?
It's not that I'm not willing to spend the money, it's just that at half the cost I am tempted by the product from Lowes.
PS...I also have a thread on preventative medicine for tomatoes here in the container forum...would appreciate your input there as well!
Pine bark is appropriate because it's rich in a lipid called suberin, which is nature's waterproofing for plants. Most hardwood bark lacks the amount of suberin found in conifer bark. As a result, it breaks down much faster. This makes soils made from hardwood bark less structurally stable and makes nitrogen immobilization (tie-up) a significant issue. Because of the rapid decomposition, heat-build up is also a frequent issue when using materials that break down quickly (think 'hot compost pile'). Finally, there is usually a high pH spike associated with the use of hardwood bark/sapwood/heartwood at some stage of the composting process that causes many of the micronutrients to precipitate and become unavailable.
For the gritty mix, uncomposted pine or fir bark is ideal. For the 5:1:1 mix, either partially (that's slightly) composted pine bark or uncomposted bark are suitable with the slightly composted getting the nod. What you see at 3, 6, and 9 in the picture below are all good for the 5:1:1 mix.
Thanks, Al, that makes a lot of sense, I will stick with the composted pine bark. Does that price seem reasonable? I can't find anything else like it around my area. I am a "club" member, so I'll get a 10% discount, but still, the price jumped 30% since last year, and I had sticker shock when I went in the shop. I will be needing a number of bags for my tomatoes.
I wish your photo had a size reference, like a dime or something. Sorry, I don't eat Sugar Pops (never did!) ;) Are they the same size as Kix? ;) ;)
I went to English Gardens today and found "100% organic pine bark mulch" and compared it to the composted pine bark. I decided on the mulch because I think the other was more than just "slightly composted". And even better, after volume purchase of 4 bags and member discount, it came to about $3.75 a bag! That means your recipe will cost me much less than buying the Miracle Gro potting soil I've been using for years! Woot!
Made another batch today, and the new mulch is much more "fluffy" than the batch I made the other day. And it smells great!!
I tried $3.50 bags from Home Depot, and $7.50 bags from a classy nursery. The fnacier bag called itself "medium pine bark mulch" and the HD bag had a much vaguer name.
The more expensive bag seemed to have been double-screned, and had much less bark powder. More annying to me, the HD bag was soggy, smelled a little fermented, and had dirt, sticks and huge bark chunks.
I guess "dirt" and "composted" matter less for an RB, but I was making a coarse seed-starting mix ... not many people reccomend bark for starting seeds!
I've browsed through the posts about your mix for the container usage and was wondering about a formula that I was contemplating to use.
The MG Potting Mix,3 bags@ 64 quart size, 1 bale 3L compressed peat moss, and 2 bags composted manure. I was thinking the manure compost would help add nutrients to the mix. I plan on using this for 5 gallon tomato containers, and also some larger tote type containers for okra, cukes, and going to try lettuce in a container.
This is my first shot at doing containers and need some help...
PS.. Is there any difference between the MG regular Potting Mix & the Moisture Control??
Everything you propose to use in your mix is fine particulates, so you can be sure your soil is going to be VERY water-retentive, so I think you're probably going to be significantly limited by too much water and too little air in the soil.
There is nothing in the manure you can't get from a fertilizer, and if you choose the right fertilizer ratio, you can pretty much have complete control over your plant's nutrition. You have no way of knowing what is in the manure or when it will be available as a nutrient for uptake because it has to break down first. That means that you'll have to fertilize, and since you have no idea what's in the manure, you're going to be duplicating a lot of nutrients unnecessarily, or growing under deficiency conditions if you don't fertilize. From this, you can see the manure has more potential to be limiting than to be a plus.
If you read the OP carefully, you'll see the emphasis is on soil structure, particularly on its ability to provide enough air in the root zone. If you keep this as your focus when you decide to go about making your soil, you won't go wrong. In order to do that, you'll need to be thinking about a very large fraction of your soil being larger particles - like pine bark.
If you embrace the concept put forth in the OP, you'll significantly increase your margin for error and increase the likelihood your plants will have the opportunity to grow much closer to their genetic potential. You'll need to invest some time, but I promise if you gain an understanding of how to manage the air:water relationship in your soils, it will be an asset that will help you in ALL your container gardening endeavors. It's literally the difference between building a soil that works for you or against you.
Kevcarr, your recipe sounds almost exactly like what I had been using for the past several years for my tomatoes in containers...and last year for peppers. I've had lackluster results with the tomatoes, and came here looking for some ideas on how to improve my harvest.
After reading Al's advice, I decided to try his recipe this year. Once he mentioned about the compaction and lack of air at the roots, I knew exactly what he meant. When I pulled my peppers out of the pots, I had all kinds of roots except in the bottom two inches or so, where it was obvious they couldn't grow because of the perched water.
I don't have any experience to share yet, but after mixing up several batches, I can attest that it is much "fluffier" and I can see that it will keep more air in the root zone. I grow orchids, too, so I get the idea that roots need air...I just never translated that to my container plants!
I've got lettuce growing in the "fluffy" now...they look pretty good, although it's only been a couple weeks. Tomatoes will be going in sometime in May.
Since you're just starting out, it might be fun to experiment and do one container with your mix, and one with Al's, and compare your results.
koshki>> As I said before, this is my first foray into container gardening, and since you have had so-so results, with a similar formula, I think I'm going to pass on mine, and give Al's a shot. It seems many people are using it, and getting good results with it. I guess my biggest problem is finding some of the components locally, besides going to the big box stores. We have a Gardenville (run by Texas Disposal Systems) store just down the highway from us and that is where we get our bulk garden soil & mulch. They don't have a pine bark mulch on their price list, so I may have to find another source for that component in the formula.
Al>> Is there any difference between perlite & vermiculite?? I've seen perlite at Lowe's and such, and have heard of vermiculite, and wondered if they could be interchanged in your formula. Also, the CRF I plan on using is the MG Shake & Feed with Calcium. Would this be a good choice??
Okay,let's try this again... MG 3 bags @ 64 qts, 1 large bag vermiculite, about 40 quarts, have to find it again.., and the MG Shake N' Feed with Calcium Fertilizer. It's a 9-4-12 with 3.5% Ca. It also has 1.4% Mg.
Still trying to find the pine bark component. The only thing I have found so far is the huge chunk mulch, can't find the fines that you talk about.
Vermiculite and perlite are quite different in that vermiculite holds a LOT more water, something you wouldn't consider a plus in most container media because most are already too water-retentive to be ideal, even w/o the vermiculite. Vermiculite increases water retention on a per volume basis and perlite reduces it.
I wouldn't obsess over the bark, but I think it is worth looking for because in the right soil it has the potential to make a significant difference in your ability to bring along healthy productive plant material.
I have consistently had the best results with 3:1:2 ratio fertilizers. I use Foliage-Pro 9-3-6 for virtually everything I grow. Miracle-Gro 24-8-16 and 12-4-8 are the nearest equivalents. The 9-4-12 is ok if that's what you want to use, and it's an ok choice for tomatoes. If you're adding lime to your soil when you make it, the Ca & Mg in your fertilizer is just a duplication of what's already in the soil, and wouldn't offer anything in the way of potential to be a plus, not even as a guard against BER in all likelihood.
I use everything that falls through the 1/2" mesh. Fines are important to my container recipe.
The larger, captured chunks will go into my raised bed, as is, to add bulk and structure. They'll eventually break down, but fresh large chunks will hold up the soil structure for aeration and drainage, and help retard compaction, at least for a couple seasons.
If I needed the larger chunks for more container mix, I'd run them through a chipper and sift again...
TX_gardener>> Thanks for the idea of the fry basket to use as a strainer. I've got one like that and I think it's a 3/8" mesh.. Let's hope, have to look in the workshop tomorrow and take a look for it. Even the 1/2" mesh isn't too cheep...
Now. Go find yourself some FREE buckets...LOL!!!
►pickle buckets at your local hamburger joint
►at your local bakery (the icing comes in 5-gallon buckets)
►from your friends who have cats (the large yelllow, square kitty litter buckets...)
Thanks for the local bakery tip. Lorelai's other grand mother works as a cake decorator at a big grocery store. I'm pretty sure she can get some buckets... I use the kitty litter buckets as project buckets when I do stuff around the house. I put all the odds & ends in them so I don't have to make 10 trips to the workshop cause I forgot something, didn't think about them for the garden.
What veggies would be good candidates for the "kitty litter" buckets??
Cabbages! Those yellow buckets come in two sizes, and the larger one is perfect for individual cabbages. They have just enough depth for the roots, and enough surface for a nice big cabbage to balance itself on.
I started the small, late cabbage transplants in those smaller ones because I didn't think they'd do anything so late. Fooled me!
But, you can also see how the bigger one would be better. The weight of a larger cabbage will tip the small bucket if it's not perfectly balanced!
>> It just seemed 1/2 was too large and 1/4 too small,
I agree with that
>> I use everything that falls through the 1/2" mesh. Fines are important to my container recipe.
One bag of pine bark mulch was too fine for that: it had a LOT that went easily through 1/4" mesh and has too soggy. But then, that year,m I also added a little of a peat-based potting mix and regretted it.
A different bag of mulch ("Medium Grade") had fewer fines, but still more than I wanted. So I used what went thorugh 1/2" screen FAST, and used a 1/4" screen to remove some of the fines from that.
Kevcarr: it looks like you hav e some slivers of white wood in your mix. Does that seem to give you any trouble?
I sifted 5 bags Saturday and there wasn't a LOT of difference except the end of the last bag it had a lot more chunks. The fibers didn't seem to be a big problem as most of them were less than 1/2" wide or thick & about 1" long. Even before I mixed everything, when you would grab a handful of the fines, the big pieces and fibers would rise to the top. I know this mix is very fast & I might add a little more peat component to slow it down just a little bit...
I was thinking I may have added a bit too much perlite into the mix, as you can see how white it looks. Will make a little test batch, a few containers worth just to see if it's any better. Got some red, yellow, and green Wonder peppers tonight, along with some Big Bertha's, and a couple Sun Sugar Tomato that need to go into containers tomorrow.
Only 1 of the Sweet 100's I transplanted in the 5 gallon buckets are doing good, the other 2 are very stressed indeed. Looks like the moisture is there, but I may have been over watering, not sure. Also lost 2 beans transplanted at the same time...
Added a little peat to the mix and have used it for some peppers and some Sun Sugar tomatoes, and they look to be doing a lot better... Getting ready to put some okra in the containers, and with 90+ highs and low 70's for the rest of the week, will just see what happens.
Finally found the lime at Lowe's and will be adding that into the mix... My other thought was the CFR was several years old and I wondered if that might enter into the equation...
Bought some new Osmocote Indoor Outdoor Plant fertilizer with the 19-4-6, if I'm not mistaken, and added about a tablespoon per bucket and scratched it into the top. I've also noticed the buckets seem to be staying more moist these last few days. I think that may be because the bucket mix is finally getting fully wetted and the water is finally staying more toward the top of the bucket and around the root system...
When I started noticing this leaf problem I was still watering on a daily basis, but since have cut back. So far I've lost the Kentucky pole beans, which were in a bit smaller buckets, but these plants were only about 6" tall. Also lost the Beefsteaks that were sowed in an aluminum pan that Momma threw in there when she was planting. Those were transplanted into some peat pots after they actually germinated. I also had some that were germinated under lights and those were much thinner than the ones started in the garden.
Not ready to give up on the container mix, but not exactly working like I thought it would.
Do your buckets have reservoirs, and, if so, why are you watering every day? If you have reservoirs, you should only be watering through the fill tube, and just to the point that the water comes out of the overflow hole.
Or, are you growing in free-draining buckets with holes in the bottoms. That's a different story altogether...
Free-draining buckets with about 5 or 6 7/8" holes... 1 in center, rest on perimeter on bottom... The pots the beans are in are about 4 gallon nursery pots. I didn't have the supply of 5 gallon buckets acquired at that time but had to get the beans out of the little peat pots, and then the weather cooled off. That's why I figured they were just kind of sulking...
Peppers are actually doing pretty good, and I have them in various sized pots to see how they react. Got some Big Bertha's and have them in a 5 gallon bucket. Woman at nursery said I could probably get away with putting 2 pepper plants in each bucket, what do you think??
Your potting mix should be staying moist enough for you to only need to water every two days. It will look much drier on the top than the moisture content deeper in the bucket. It took me quite awhile to accept that the top 1" or so could look bone dry, but there was actual moisture in the rest of the bucket. There was...
And, for future buckets, I might recommend more drainage holes on the bottoms, and some holes on the sides, about 1/4" up from the bottom, all the way around.
I've never grown more than 1 pepper per bucket, but you could try and see what happens. I'm thinking competition for leaf space and sun if they get too thick and bushy...?
When I pulled the dead bean & tomatoes out of the buckets I scooped down and found out how moist the mix was down deep. I guess I've way over-watering these pots and haven't for the last 3 days. Checking deeper today they are still moist down about 1 1/2", so I will start watering again tomorrow, and use less water. Since I haven't watered the borderline plants seem to be coming around. Maybe I can save a couple, but will reseed the beans again and give them another chance.
Kev - it would be helpful if you got a wooden dowel or skewer, thin enough to sharpen in a pencil sharpener and long enough to reach deep into the pot. Insert the sharpened dowel and withdraw. Check it on your cheek or inside of your wrist to see if it feels cool, or note if it's visibly wet or dark/dirty. If there's evidence there is moisture deep in the pot, withhold water until the dowel comes out clean & dry.
Thank you all, just a little bit ahead of you guys, and girl, about checking a little deeper in the container. I've been using bamboo sticks for support and when I really looked at one and noticed how wet it looked. That's when I started digging deeper and found out moist the mix really was. Now I realize that I may have been a little hasty about my determination that the mix was too fast and wasn't holding water. Our 90+ temps have helped these pots dry out fairly quickly and I might be able to save a couple of the Beefsteaks.
Now that I'm aware of how water retentive this mix is I have cut my watering schedule way back, even though we're hitting 90 every day and when I check the soil a bit deeper you can tell how cool it is.
Watering technique is significantly under rated in its importance to container culture. I think the ultimate container gardeners are bonsai practitioners; this, because the work in shallow containers, which are much more difficult to grow in, they are growing in very small volumes of soil, and they are continually adding the stress of regular manipulation of their plants to the other adversities; so bonsai is container gardening raised to the Nth degree. I said that to give more impact to the thought that when a bonsai master takes on an apprentice, the apprentice time is usually dedicated to learning to water properly and in a timely manner before he is allowed to work on trees.
Of course, watering technique is closely linked to soil choice, and soils that hold too much perched water often don't allow you to water properly until the container is jammed full of roots so the plant uses the excess water the soil holds before it rots roots. Note though that just because there is no root rot is no good indicator that there is no inhibition of root function taking place. Any time the soil is soggy, root function is impaired and potential lost, no matter if there are rotted roots or not. Roots die quickly under airless conditions, so when the soil changes back and forth between soggy and containing enough air, roots die and regenerate with the cycle. The energy that goes into replacing the lost roots is the lost potential because the energy might have been put toward producing additional blooms, fruit, or in simply increasing biomass.
It's funny that the symtpoms of too little water can also be caused by overwatering: it doesn't matter how much water is in the pot, if there are not enough healthy roots to take it up.
Too bad we don't think about the necessity of adding fresh air to the soil! Maybe if we had to bring home little bottles of "horticultural air" from the nursery, and pour them into the soil every few minutes, we would remember how important air is to roots.
High school environmental science needs to be re-evaluated, or at least taught to me again, it's only been 40 years... Of course, the only thing I can remember is that roots drink water, photosynthesis exchanges carbon dioxide for oxygen and Loraine C., my lab partner, was real cute with her Brooklyn accent...LOL...
And breath oxygen. In the dark, as I recall, even leaves absorb oxygen in order to keep metabolizing.
Rotts of real aquatic plants (I think) get their oxygen via sap, exported by leaves. I suppose they might get some oxygen from gas dissolved in water, but my guess would have been that mud (like in rice paddies) is hypoxic or anearobic.
I would have said that "roots don't have gills", but they do have root hairs which might be almolst as effective.
Plants don't actually drink water. They absorb it molecule by molecule from colloidal surfaces and from vapor in macropores. Plants use CO2 for photosnythesis, and O2 is a byproduct of their metabolism, but they need O2 in the root zone for normal root function and metabolism. If soils are soggy, they CAN adapt to some degree, but they don't handle the back & forth transition from saturated to well-aerated without rebelling.
The roots produced under hypoxic (soggy soil) conditions or under water are quite different from those produced in a quality container soil or other well-aerated medium (perlite - screened Turface - calcined DE - seed starting mix, e.g.). These 'water roots' are much more brittle than their counterparts growing in soil; this, due to a much higher percentage of aerenchyma (a tissue with a greater percentage of intercellular air spaces than normal parenchyma), and their construction is different as well.
Aerenchyma tissue is filled with airy compartments. It usually forms in already rooted plants as a result of highly selective cell death and dissolution in the root cortex in response to hypoxic conditions in the rhizosphere (root zone). There are 2 types of aerenchymous tissue. One type is formed by cell differentiation and subsequent collapse, and the other type is formed by cell separation without collapse ( as in water-rooted plants). In both cases, the long continuous air spaces allow diffusion of oxygen (and probably ethylene) from shoots to roots that would normally be unavailable to plants with roots growing in hypoxic media. In fresh cuttings placed in water, aerenchymous tissue forms due to the same hypoxic conditions w/o cell death & dissolution.
Note too, that under hypoxic (airless - low O2 levels) conditions, ethylene is necessary for aerenchyma to form. This parallels the fact that low oxygen concentrations, as found in water rooting, generally stimulate plants to produce ethylene. For a long while it was believed that high levels of ethylene stimulate adventitious root formation, but lots of recent research proves the reverse to be true. Under hypoxic conditions, like submergence in water, ethylene actually slows down adventitious root formation and elongation.
In essence, the structural variation of roots that forms in aqua culture allows the roots of the plant to get oxygen needed for root metabolism from plant parts above the ground instead of from the soil, as they normally would. The reason saturated soils in conventional container culture are so limiting is because roots cannot make the transition from a media that is hypoxic part of the time and well-aerated the rest of the time. The roots, when deprived of oxygen, simply die or are significantly impaired in function until aeration returns to the soil, a condition that is often seriously limiting and can even kill the plant outright.
>> don't plant leaves "breathe" carbon dioxide and "exhale" oxygen?
Yes, when the leaves get enough light to convert the CO2 to O2. That take a lot of energy and reducing power.
In the dark, the plants can't produce oxygen. No photosynthesis. And yet a plant still has energy needs, so at night it "respires" - taking up oxygen and burning stored sugar - to keep it going through the night.
Even in heavy shade, more O2 is produced during the day than is consumed at night.
Roots never photosynthesize (even grown in wtaer and sunlight, they have no chloroplasts). Therefore they need oxygen all the time.
I never knew they could make their own internal aerenchymal snorkles to suck air down from above, but I learn something almost every day here on DG. Thanks, Al!
Thank you for the information and the link you sent. I'm pretty sure I understand the concept of the "'Gritty Soil", although there is alot to absorb and I'm sure there are some things I missed or didn't quite understand. The actual concept just makes sense... I will be heading out this week to buy the necessary parts. - I can already "see" my plants that I consider healthy now, becoming what is probably more healthy and starting better lives.
My confusion lies in the fertilzer. I just reread and got a grasp on the ratios, so that is no longer a question. The liquid I have/use for my house plants is MG 8-7-6 and that is clearly not a 3:1:2 ratio. I guess I will pick up a new one with a proper ratio while I'm out.
Do you fertilize every time you water since the soil is not already enhanced with such fertilizer as you would find in say... "MG Bagged Mud"?
I have some good looking Peace Lilies, Split Leaf Philos, Christmas Cactus, Budda's Hand, Scheffelera, Austrailian Tree Fern and some other random house plants that I feel will benefit greatly by this change. - Also I have posted a picture of another PL that my MIL asked me to place in ICU for her, as she nearly killed it (you may have read the thread in the Beginner Houseplants forum).The poor thing looked awful, and though it is still not (in my opinion) up to par, it does look much better than when I brought it to my house weeks ago. -- I am thinking of it being one of the first to be transplanted in the "gritty soil". Should I bare root it or since it is a bit of distress, should I just remove a good portion of the current soil and place it in the new soil, and try to remove the rest at the next repotting interval?
Though I have a number of succulents, most of my plants are bonsai or potential bonsai. I over-winter about 100-125 plants under lights. Those, I fertilize (during the winter) each time I water with a very low dose of FP 9-3-6 - 1/4 tsp per gallon of water. What allows me to do this is the free-draining soil. All of my plants are situated above a plastic dinner or salad plate that serves as a collection saucer, and I flush the soil each time I water. It is extremely effective, and you've all seen the hundreds of pictures of perfectly healthy plants that serve as witness to the effectiveness of that method. Remember though, you couldn't possibly fertilize this way when using a soil that is so heavy it requires you water in small sips to stave off the specter of root rot.
In the summer when all the temperate plants that snooze the winter away in an unheated garage, all the tropicals from the basement, and the dozens of display containers I scatter throughout the gardens & decks are actively growing, I couldn't afford the time to fertigate by hand each time the plants need a drink; so for summer I water with the hose & try to fertilize weekly as temperatures allow. It's probably almost as effective as fertigating @ every watering, but you could fertilize every 2 weeks if you're diligent & probably not notice a significant difference in any of the 3 intervals. I think if you start stretching it out beyond 2 weeks you'll start to miss potential that might be noticeable - and it's difficult to quantify lost potential because it's based on how much better a plant could have been. Often, growers think their plants are perfectly healthy and describe them as such when there are significant limitations in play that go unrecognized. Unfortunately, lost growth potential in plants is forever; it can never be 'made up for'.
For your peace lily, I'd bare-root if you're moving to the gritty mix from a heavy soil to avoid any issues that so often occur with dissimilar soils in the same container. Keep the roots moist at all times when repotting so they don't dry out. Don't worry if some of the foliage collapses after the repot - the plant should recover nicely and quickly leave you feeling rewarded for your efforts.
Al: For non-cactus plantings, is the 5:1:1 mix better than the gritty (1:1:1) mix for typical plants? That is, if I am willing to change the soil annually, is 5:1:1 better than the gritty mix? If not, why not use the gritty mix for everything?
The gritty mix is excellent for cacti/succulents because it supports virtually no perched water to worry about (rotting roots). The 5:1:1 mix is still head and shoulders above most commercially prepared cactus soils, but not as good as the gritty mix because it does hold some perched water.
There is some confusion about the 5:1:1 mix's longevity. Personally, I only use it in containers that will go 2 growth cycles or less between repots, but that's just ME. Conifer bark, on a size for size basis, breaks down at about 1/4-1/5 the rate of peat and 'composted forest products'. Add the larger size of the bark particles, and it's much slower than that, even. Structurally, the 5:1:1 mix should outlast a peat soil by at least 6-7 times. In almost ALL cases, the plant needs repotting long before the soil is no longer servicable, something that can't be said about most soils based on fine particulates.
I use the 5:1:1 mix for my short term plantings because it's less expensive and easier to make. I realize I give up a small amount of potential, but I can live with that because plants are generally soo much more productive and healthier than those in heavier (more water-retentive) soils. Once you're used to the soil and your plants watering requirements, I think you would be pretty hard-pressed to discern any significant difference between the gritty mix and the 5:1:1 mix unless you get into trouble watering. The gritty mix is much more forgiving of over-watering, and growing in shallow containers.
If you use a soil that supports 3" of perched water in a 3" deep container, the soil will be 100% saturated after a thorough watering. That can't happen with a well made gritty mix.
Thanks Al; that makes sense. I also have the impression from other postings that the 1:1:1 mix holds less water than the 5:1:1 mix, so for water-loving plants, 5:1:1 is the better way to go. Is that right?
Al, thank you seems so insufficient of a word for what you have brought to DG, but non the less, thank you so much.
I lived up in northern Ohio for 8 years and when I started a flower/veggie garden in ground I kept trying to teach the members of my garden club that you have to have light soil and I accomplished this by incorporating leaf humus in with rich top soil and horse manure. Within one season they could not believe how well the plants were thriving. They had drainage on top of clay soil that was the norm for the area.
Now I live in Florida and only have room for containers, I'm especially interested in growing tomatoes in grow bags (not the plastic ones). I’ve decided on grow bags for the breathability for the roots.
Do you think the material grow bags along with your mixture, to be ok and not too much aeration?
I'm going tomorrow to go out and start trying to find your incredients.
Hi, Jan. Thanks so much for the kind words - much appreciated.
The bags will work well, but if they are resting on the soil, you'll essentially be growing in mini raised beds, so you'll be able to get away with a soil much heavier (more water-retentive) than you could in a conventional container.
The relationship of the bag's design to aeration is sort of an obscure one. Technically, the bag has nothing to do with how well-aerated a soil is - primarily a function of soil particle size, but there's a twist that needs to be considered because it affects water retention, which DOES affect aeration. Because when these bags are resting on the ground the earth acts as a giant wick and pulls excess water from the soil, perched water isn't much of an issue. The Miracle-Gro soil that might have been much too water-retentive to allow you to water properly in a conventional container might be well-suited for use in a grow-bag.
Please make sure you give that some consideration when you formulate your soil.
I'll be around if you need help. Sorry I missed your earlier post - I've been terribly busy with my (bonsai) trees and gardens, as well as in the community.
I'm planting to have the grow bags up on wire stands so the water doesn't pool at the bottom, as this will help the bags last longer. I was just so excited to find the pine bark fines, after reading that so many had problems.
Yes I totally understand being busy in the garden, when I lived up north, most of my time was outside in the garden or with my collies outside. I love the outdoors, but now that we are here it is limited to early morning or late afternoon.
This is a bit off-topic, but I'm curious what you amend your garden soil with (that is, for when you are not using containers) and other folks may be as well. Is there a thread on that subject you can direct me to?
Thanks, Al. I add compost too -- but haven't been adding the pine bark fines since they are a tad pricey here (I need a different source...). Many years ago I would add coarse sand as well (and peat) to break up my clay soil, then I heard that sand was frowned on; but where I added it my awful clay soil is much loamier. I was wondering how to translate your container principles to other situations...
>> Many years ago I would add coarse sand as well (and peat) to break up my clay soil, then I heard that sand was frowned on; but where I added it my awful clay soil is much loamier.
I had the exact same experience: "everyone" says clay plus sand equals concrete. But it does help my very heavy clay to be more friable.
(And then, maybe it is something like "it's easier to work some temporary structure into friable clay than into pudding". I wouldn't call it "good tilth" but it is a half-step into that direction.)
My theory is that sand doesn't do the same things that compost or organic matter do. And it seems to be most beneficial when the clay has almost no OM, silt, sand, grit or structure. The benefit is still noticable until the soil becomes fairly organic, with OM that does not disapear in a few months. Perhaps soil fungus or small root fragments start providing the micro-structure at that point.
Clay without OM has no life or structure or aeration, so it is no better for roots than mortar would be. It doesn't matter whether or not the mortar has sand - that clay needs lots of OM before it can ever be GOOD soil.
I wrestle with my cheapness and wheelbarrow to get enough compost into clay. The first year, I might not get more than 10-20% added. Probably 50-75% compost is what is really needed! OM just disapears into raw naked clay and sand while the soil life builds up and slow-digesting OM builds up. So my beds usually spend their first 3 years starved for "enough" OM.
However, WHILE it is still poor, clayey, low-OM soil, some sand or grit makes huge sticky blobs MUCH easier to break up with a fork, hoe or rake. And they stay broken up longer than sticky sand-free clay would. Like dusting sticky hard candy with powdered sugar: clumps don't stick as fast or as hard and air is more liekly to remain between peds. Without the sand or grit (or bark) the pure clay peds would deform and revert to airless puidding. I think that is the beginning of "tilth".
Perhaops a little "conc rete" nature is better than pudding-soup nature! If the peds and air channels are stiff enough to hold up, you might get som ne aeration and drainage for a season or tow.
Maybe I should say sand only adds friability at low OM levels - maybe it adds small scale stiffness (reduced pliability?) and tghatg aids strcuture and hence drainge? This is a new line of speculation, that occured to me as I'm replying.
With the addition of around 20% compost, sandy-gritty clay seems easier to work into peds that support a few air channels, than soupy-pudding-clay + 20% compost is. Probably, a few months after adding 20% compost, it is down to 5% OM plus 5% very hungry soil organisms.
I may be wrong, but it seems that way, the way I work with it. And sand or grit don't decompose in the first 6-12 months the way compost or peat does! Grit is forever.
Since Al turned me on to pine bark, I've been buying various kinds of mulch and screening it. That seems even better than sand and grit at opening up heavy clay. Bark shreds are longer than grit, and a bark shred has a better aspect ratio (longer than it is wide) than sand grains. They don't find it as easy to pack tightly.
And I imagine that bark can "absorb" a little clay. A few 1-5 micron clay grains can probably nestle into pores and cracks in bark chunks. At least that keeps SOME from being transported into air gaps where they wsould plug drainage and aeration. Sand and grit can't do that.
It might be true that if you mixed clay with sand and then soaked the result and pounded it flat, the clay would "run" and fill every gap and the result it would have no more air than adobe.
But if you mix clay with sand-grit-bark, not-too-wet, fork them up a bit in the raised beds, tamp very lightly so only the surface compresses, and then avoid soaking or pounding flat, they might hold up enough to sustain SOME air channels for a season. At least until the next turning when you add more compost. People who know good soil might not call that structure or tilth, but it's the best I've got until roots start upholding the soil and worms maintain the infrastructure..
I would urge you to consider even the cheapest, crummiest bark mulch (properly called logyard waste or "Home Depot mulch") over using all sand. Don't use cheap mulch in pots, but it adds coarse, slow-disintegratin g OM to outdoor soil. And a cubic foot of bark is much lighter and cheaper than a cubic foot of sand!
And crushed rock in 2-4 mm sizes is better than any bagged sand I see for sale, which is usually 50% fine sand (0. 2 mm, 0.1 mm and smaller).
The kind of improvment that I talk about is not changing "good" soil to "best" soil. It is about changing "unusably bad clay" to "poor but usable soil" in one year, cheaply.
Then I keep adding more compost and mulch for a few more years, and it becomes what I think of as "pretty good soil!!!"
If I ever work with actually GOOD soil, my rating system might chnage. Right now I am an easy grader.
Tapla, what do you use to screen the turface, pine bark, etc. (I know you use hardware cloth, but HOW do you do it)? Do you build sieves for that? Do you have photos of yourself at work? I would think that process would be slooowwwww but you have indicated it isn't.
You could build a screening table, if you're inclined to do that. The plans are pretty simple. Build a frame of 2X6 OR 2X8 square just a little bit bigger than whatever cart or wheel barrow you plan on using. Build another table frame large enough for the cart or barrow to be pushed in place underneath. On what would be the front end extend the frame about 4" to 6" to be a pivot for the inner screen. Drill a 13/16" hole with the inner & outer frame aligned. Install 3/4" pipe just a bit longer than the outer frame and use pipe caps to close it in place. Have a second wheel barrow or cart at the front to dump the "larges" into as you sift the bagged material. I would use 3/8" or 1/2" hardware cloth, only problem is finding the 3/8" so use 1/2" because it's also a lot cheaper.
A couple notes & something I forgot before. Make sure you extend the outer frame lone enough so when you dump the screen it will clear the frame and be easier to empty. Make sure the legs, 4X4 PT posts, are a comfortable height to work with, and attached to the outside of the outer frame, so your work area is right in front of you, and you're not stretching across to get stuff that gets away... On the "tail" of the outer frame attach a 2x4 from side to side to create a lip for the inner screen to sit on while you're sifting.
Use garage or fence type door handle to attach to the inner frame to dump it. If you want to make a second frame with different size mesh, you could do that and just pull pipe and switch out screens.
I hope this helps...
You kind of beat me to it but your pictures are great. I just added the outer frame and dump feature to it.
Happy: This was more of a concept for a screening table than what I actually built. Tapla's pictures are great and you could use them to build my table. If you have some woodworking experience it would help greatly. It's all just simple cuts with a table saw and simple joinery.
On pic #1, it shows the simple inner frame with 1X4 white boards. Measure to size you need for your carts or wheel barrows. Photo #2 shows the half-lap joints. You would you these joints to make all your framework. For the outer frame make the inner width about 1/2" larger than the inner frame so it will just slide in & out when you dump the inner frame "larges" that remain after sifting. I would use 2X6 to make the outer frame because it will hold all the weight of the frames and the sifting media. 4X4 Pressure treated posts would make the legs. I have air impact tools so it makes my work a lot easier!!!!
In Photo #3 it shows the handles on the side of the frame, on mine put them on the upper side of the frame so it will nest in the outer frame when you're sifting. They will be on the "tail" end of the frame so they will be out of the way while you're sifting.
For the brace to hold the inner frame in the outer frame just use some of the extra 1X4 white board the width of the outer frame. Attach it to the tail and side frame leaving about 1" creating a lip to hold the inner frame inside the outer frame.
With the inner frame built & sitting inside the outer frame measure and drill the 13/16" hole through both frames to hold the 3/4" Galvanized pipe to use as the hinge. Buy 2 caps for the pipe that way you can pull the pipe out to change inner screens when you sift different materials, just build another inner frame. Use your first frame as a template for subsequent frames.
If you still are having any problems give me your dimensions and I'll draw up a set of plans for you. One of the other real important things to remember is to make sure you get straight board material. It's a real pain to build with wood that looks like a propeller!!!
If you have any questions please send me a d-mail...
I screen Turface over aluminum insect screen & use what doesn't pass. I save the fines to use in raised beds, the 5:1:1 mix for added water retention, or hypertufa projects.
The grower grit or #2 cherrystone comes prescreened, so I screen that over insect screen to remove the dust, and do the same with my bark, which I'm also able to purchase in 1/8-1/4" which is ideal. If you're using pine bark, you can use what passes through a 3/8 or 1/4" screen and what doesn't pass a 1/8" screen.
Hmm, I try to get rid of anything that passes through a 1/4" screen. But that's only about one year's experience, and last year I did add some commerical mix that added fines, and probably did not do a totally through cut with the 1/4" screen.
I would defer to Al's greater experience and analysis!
But I WISH I had some 3/8" screen, or 3-per-inch mesh.
Using the 1" chicken wire is rare for me, but I was chopping green juniper boughs with a lawn mower before adding them to the compost heap, and did a quick cut to pull out what needed the most extra chopping.
If you know that most of your mix will pass quickly through a screen, just lay it on top of the support, so that you can rub it 1-2 times, then lift the screen, shake, then flip the left-over chunks aside.
I'm thrilled to tell you that your advice has really paid off! I harvested my shallots yesterday, and I can't believe the results!
Last April I planted 6 cloves each in 4 pots in the 5 : 1 : 1 mix in 14 " diameter clay pots. I set them on a narrow strip of garden that happened to be the exact width as the bottom of the pots, which turned out to be the perfect spot.
The 24 cloves (about 10 oz.) of shallots yielded 139 cloves and 3.75 pounds of shallots!
Here are some pictures! Most of the bulbs were a good size...much bigger than what I planted.
Between the better potting medium and now understanding perched water, I have finally had success with shallots!
What I get for the time I spend here is the thrill that comes from learning that I might have made a difference in someone's growing experience. That's really the only reason I'm here. In a way, it's a selfish thing because I get so much satisfaction from knowing you advanced your skillset and managed to squeeze some additional reward from your growing experience; so thank YOU for letting us know of your success - and another big thing, for sharing your enthusiasm.
I did do a lot of things differently this year, including using the 5 : 1 : 1 mix. I also used mycorrihzae at several points, and Azomite for the micro-nutrients, plus the Foliage-Pro and some seaweed. They have also been treated regularly with Daconil and Actinovate, and I even have used aspirin to boost their immunity.
They are just now getting ripe, but each plant has more than 20 tomatoes on it. I've never had such productivity before. Of course, the good weather in June helped a lot. Oh, and I'm using an electric toothbrush to help pollination.
One last thing I noticed... I can see all kinds of roots even at the surface of the pots. Not sure if that is from the medium or the mycorrihzae? Probably both!
Oh, yes, the electric toothbrush! I learned about that on the Tomatoville forum. Touch the back of the open blossom with the back of the running toothbrush. Occasionally you will see the blossom expel pollen, but it's not necessary to work.
Tapla, i just joined DG and started with these three threads of yours. Thank you for all the time and information that is available. Just one problem though, could you write one post for those who live in the jungle with only the materials provided by nature. Some of your ingredients are just not available here and as to fertilisers we only have commercial grade Urea, Ammonium Nitrate, DAP diammonium phosphate, NPK, etc. Now, how to play around with these?
Scheesch, after a lead-in like that, I have to say that I don't know what I can do to help with soils unless Kamasud tells me what he has available that might fit the bill as replacements for what we take for granted in the states. I think what's most important, is gaining an understanding of how soils work and the concept of making well-aerated, fast draining soils work for you, instead of having to fight them tooth and nail every step of the way. The concept is so much more important than any recipe I might provide.
Al, the basics of the how and the why/how things work, and work together, are the crucial foundation to figuring out what one can use the its fullest potential... or, so I believe. You seem to have the most in-depth understanding and knowledge of all this of any person I have ever 'spoken with' about this, and I talk to everyone I can get my hands on about soils. But, while (as the saying goes) some people 'know' and some people 'teach', you have a very rare gift of both; you explain things in such a comprehensive fashion that even a Pollack like me can understand it clearly, and the fact that you generously come in here to the forums and share your knowledge in such a gentlemanly manner is more appreciated than you will ever know. God bless you. =)
While I don't post much in this area, it is in my "top 3" favourite threads to read in here, to just read and learn, and walk away feeling smarter! =) And yes, sometimes my BDH will come along and see me reading about "dirt" and tell me I'm slightly odd. ;) LOL!
Well, that was an exceptionally kind compliment. Thank you!
You don't become an accomplished container gardener by luck or accident. Someone brand new to container culture can become accomplished in a VERY short time if someone is willing to provide the basic framework. Once growers acquire the knowledge, it's time to let it bear fruit through its practical application, and it doesn't take long.
I'm limited in what I can say without it sounding boastful; at least I think I am. I'm not good at determining how I come off to others in my day to day posting. 10 years ago, I wouldn't have allowed myself to be as direct about how important soils are in determining a grower's ability to consistently produce attractive and productive plants. Light is important, but a grower can change the light by moving the pot, leaving your soil as undoubtedly the single most important consideration for your conventional container plantings. Yet, outside of those who belong to a forum site or MAYBE a garden-related club, soils are rarely the topic of conversation. That's something akin to your doctors ignoring anything to do with your heart.
This is the part that sounds boastful, but I think it's something that should be said, no matter if someone does happen to think it a boast. I've taken hundreds, maybe thousands, of new and struggling growers under my wing, and taught them exactly what I'm sharing here, + some information about nutritional supplementation. Never, has anyone regretted it, that I know of. Every person was very excited about their new found ability to grow plants very notably better than they were formerly able, and better than a high % of other growers with years and years more experience than the fledglings. Growers that have no knowledge of the concept outlined in the OP are at a distinct disadvantage - there is little question about that. I'm not saying that because I wrote it, I'm saying it because the thousands of growers I've had intercourse with prove it to be true beyond any question.
For the most part, though, they did all the work. I would primarily forward links to various threads I wrote that explained things. All I did on those threads was assemble some knowledge from various sources, including my own experience, that I thought important - trying to put it in a form that could be understood by everyone. I'll take credit for that small part, but essentially they did all the work, their enthusiasm and open minds being their greatest assets when it came to learning and ensuring their progress.
I've been around long enough to have learned that the value of experience varies from less than worthless to critically important. You might ask, "How can the value of experience ever be less than worthless?" It can, when it's an impediment to progress. As an example, I'm certified as a CCW (carry concealed weapon) instructor, as well as being certified to teach several other disciplines. In many cases, students arrive thinking they know much more than they do (most often the young men), and with a lot of baggage - translated, that means bad habits they acquired as a result of their 'experience'. People are often reluctant to change anything they're doing when someone suggests there might be a better way. That stubbornness comes from an inability to admit to themselves that anything about their habits could possibly inferior. Stubbornness doesn't get you any farther in your growing abilities than it does in a firearms discipline class, the difference being clinging to old, less than desirable habits in a firearms class isn't an option. Here, it's completely optional & no one cares if you do or don't avail yourself of the information, but that doesn't change the potential effect it could have on the growing experience. Those that understand the concept will always be able to use it to enrich the growing experience. Those that aren't aware of the concept, don't understand it, or ignore it altogether, might not see any change in their growing experience (which in itself is a bad thing), but the hit comes in the form of lost potential - what could have been if the concept was put to work for the grower, instead of it being ignored so it works against the grower.
OK - end of the line for my musings. Thanks again, Speedie.
What we know can be measured what we don't know can"t be measured which way does the scale tip
before I read this awesome post I did not know that there are 6 teaspoons per ounce
treatment at 2 teaspoons per ounce of 3% H peroxide or 16 ounces treats 48 gal of rain water helps eliminates the misquito population and helps our plants
I read the MRI study on plant roots what we know is obivious
why we grow a plant to this point beautiful foliage strong root system so we tear it apart and repot as usual well try this dont tear it up take a larger pot put pearlite or beanbag beans (Walmart has a 100 Litre bag for 11.95) in the bottom to bring the plant to proper height fill in around the sides to 1 inch below the lip dirt on top to keep the beans from floating away the plant has not been disturbed just relocated in its former healthy and vibrant state drainage is good more oxygen is accessable to the roots. I have implemented this with a few plants and will take pictures 1 day 1week each month there after It makes sense to me may be you would also try it.
Relief to know I will never know how much I don't know
Sorry tapla, a bit tardy in responding. Got some health issues and some times life does get to much, at that point i leave the forums alone. You never know what you may write and what it turns out in the end. That is what i was eluding to at the welcome mat.
I read everything you wrote about soils and i am impressed. Emphatic attitude is required when dealing with plants and that ingredient you have in abundance in order to get down to the micro level to find out what's ailing plants.
What ingredients are available:- Well if you go back in time about 100 yrs and the ingredients available to you then, are what we have now. I am a bit confused, organic manure (any type), sharp river sand, these kind of things which a gardener always has in his repertory.
Chemical fertilisers. HuuuM! I am afraid commercial grade only. Urea, in abundance. NPK 17/17/17. DAP 3/1/0. Ammonium Nitrate (hate it for its raw fuel oil smell, reminds me when i was quarrying for marble, cheap explosive ). GROW MORE is available at garden centres. Peat and Coir, abundant.
Any way what you wrote and what i have read (found) so far illustrates so well what is going on at the micro level in the soil, i get a picture and knowledge of what to do.
Just wanted to let you know that I'm still picking tomatoes (a couple dozen today), and while the plants are starting to look a bit stressed, they have lasted far longer than I've ever been able to grow them. Usually by late July or early August they would succumb to some form of blight. Today they look fabulous, and are still blooming!
I threw a lot at them this year. Your 5:1:1 mix, mycho, Actinovate, Daconil, seaweed extract and even aspirin. I'm really interested in looking at the roots once these guys are done, which may be a while. In each tomato container, I have got so many fine roots at the surface that I can't really stick my finger in to see if they need water. It's like a thick mat of fine roots! I usually water daily...sometimes they get droopy before I get out there.
My only problem I really had was that the plants overgrew the 6' cages and then became unstable in wind. In past years my DH would bungee them together, but that led to poor air circulation and disease. This year we didn't connect them so closely. He used one of his 65# bar bells to bungee the lead plants to and then we interconnected them, while still keeping as much space between them as possible.
Anyway, this led him to ask, "would you like to use this strip of grass next to the patio for a raised bed instead?"
So that got me to thinking about what medium I should put in it. It will be on the ground. But I have been so happy with the 5:1:1 results, I was thinking about using it in there.
I'd go with something heavier than the 5:1:1 mix, so you can keep up with the water demands. Remember, the earth is going to act like a wick and remove all the perched water, so a soil as porous as the 5:1:1 mix will dry quite quickly. 50-60% topsoil, then some pine bark fines and MI peat (reed/sedge peat) should make a good soil. I helped Gymgirl figure out a raised bed soil, but I don't remember what we came up with or how she did - haven't talked to her since spring. Maybe she'll see this and add her thoughts and observations to the conversation - I'm curious myself.
This is what's in my raised beds (see picture). It's a combination of PBFs, reed/sedge peat, sand, and Turface. At first, there was a lot of shrinkage, due to the high % of OM, but as I added the used soil from my bonsai pots, a larger mineral fraction and less shrinkage was the result. If I was building a raised bed today, I think I'd use just what I suggested to you, + some Micromax or other source of insoluble micronutrients.
I wish I would have seen this site before I repotted my two peace lillies. I definitely did not use the right soil and my older PL is looking pitiful. Hopefully I can get it to last through the winter before I buy the items for your basic mix.
You wrote earlier: "I use #2 cherrystone, which tends to run a little larger than grower size in the Gran-I-Grit. I'd say it's about 3/32 - 3/16. [So he really means the larger size.] You can use larger, but here's the deal. When you use disparate sizes in your material, it has more of a tendency to separate, and the soil takes on the characteristics of the two ingredients that are closest in size. IOW you can use large grit, but if you bark is also large, the soil takes on (primarily) the characteristics of the bark and grit."
I am sifting the pine bark through 1/8" and 1/3" sifters (just keeping the stuff that goes through the 1/3" sifter and doesn't go through the 1/8" sifter) but the developer size grit pours through our 1/8" hardware cloth.
One other question. I read: "You'll need to be mindful of rain, because if you leave your gritty mixed plants out, you can have a washout problem." I was planning on using the gritty mix for outdoor containers. What should I do to avoid erosion?
Actually, you want grower size - which comes prescreened 3/32-3/16". The idea is to keep the particles JUST above the threshold where perched water starts to accumulate, which is at .090 -.100. The decimal equivalent of 3/32 is .094. We like the bark a little larger (1/8-1/4) to allow for some breakdown over the life of the soil.
Developer grit is 3/16-5/16. With the holes in 1/8" mesh being about 2/16", it's not possible for it to pass through 1/8" mesh in any volume. Are you sure you don't mean 'starter grit'? I use that occasionally, but not often at all. 1 bag of the starter grit lasts several years, and I go through about 10-12 bags of #2 cherrystone or starter grit each year.
I'm not sure who posted the warning about erosion, but it's not a concern. If you turn a narrow hose spray under high pressure on the soil, you can wash it away, but I'd say it's pretty near impossible for even the hardest rain to wash away the soil, unless it's heaped up higher than the sides of the pot. If you keep the soil line at least 1/4" below the pot rim, it will be perfectly fine - you won't lose any soil. Use a water break (this is the BEST - http://www.californiabonsai.com/product-category/watering-tools/ ) when you water & it will never be an issue.
Do I have the numbers right? (see image)
Perching starts when the grains get down to around 0.090 - 0.100 inches (2.286 mm to 2.54 mm) diameter.
3/32" is 0.094" is 2.4 mm.
Is it true that, if the mix has even 10-15% by volume smaller grains, perching can be expected even if 85% of the mix (by volume) is larger than 3 mm (0.118")?
I'm picturing 1 small grain lodging between many or most of the big grains, making the pore size linear dimension much less than half what it was, hence being very prone to perch water.
Would a rule of thumb be something like "if you have any small grains, the large grains should outnumber them by 2-3 to 1 if you want to decrease the amount of perched water significantly "?
In other words, I should KEEP 1/2 or 2/3 of all voids FREE of smaller grains.
Don't hesitate to say "it doesn't work like that at all". You won't hurt my feelings.
I'm starting to think that I can EITHER avoid perched water, OR have any upward wicking of water, but not both with the same mix.
I might change my goal to "maintain enough open air channels all the way to the bottom of a cell, and avoid excessive water retention near the top of a cell (to prevent damping-off).
I've been convinced of the value of bottom-watering seed-starting cells like inserts and propagation trays. But that requires some wicking. I was trying to provide enough wicking and sufficiently little perched water that roots would thrive all the way to the bottom of a 2" deep c ell.
>> "You'll need to be mindful of rain, because if you leave your gritty mixed plants out,
>> you can have a washout problem."
Speculating, maybe this person was concerned that some finer component in his mix, if any, would wash right out and away from the coarse phase.
Tapla: Ah - I misunderstood -- I thought the point was to have all the components the same size. That is very helpful. We have both starter and developer grit -- I'll check tomorrow. Maybe the screen isn't 1/8" as I had thought.
What size should the Turface be screened to?
Re erosion, I'm wondering if I need to make the holes in the bottom of the pots smaller than I might otherwise. (In the past I would cover the holes with a layer of newspaper which seemed to work ok to hold the dirt in until the soil stabilized, but I'm sure that is not appropriate in the new world of Tapla.)
I screen the Turface over an aluminum insect screen & use what doesn't pass. I cover the holes in my pots/containers with a piece of fiberglass window screen or a piece of plastic canvas (hobby shops) made for needlepoint projects.
And I just focused on the fact that insect screening is finer that 1/8 hardware cloth -- Wikipedia says "The fineness of a screen mesh is measured in wires per inch on the warp (length) and the weft or filler (width). An 18×14 mesh has become standard [for insect screening]; 16×16 was formerly common and other common sizes are 18×18 and 20×20."
I would have thought that insect screening is too flexible to use to sift turface or grit -- that it would sag under the weight?
From a technical perspective, Turface MVP is just a little too small to be perfect in the gritty mix, but it's as close to perfect as I've found. If you screen the fines out through insect screen, the remainder isn't small enough that it clogs the air pores between the larger ingredients, which make up 2/3 of the mix. Basically, we make a little compromise in using Turface a little smaller than perfect so we get more usable product from a bag.
Ok, that's excellent. I've made up screens like yours (actually, my dad used to screen compost so I have some 60-year old screens!). I was worried that insect screen wouldn't be sturdy enough, but I'll try to find some metal insect screening instead of the soft fiberglass stuff that is sometimes used.
>> What does 40 mesh, 30 mesh, etc. mean? 40 to the inch?
That's how I've always seen it in hardware catalogs. The link that I got those "nominal sizes" for called the sieves "#30" and "#40", but that MUST mean the same thing.
Yet the nominal openings depend a lot on the thickness of the wire and how you weave it and weld or glavanize it! Or maybe these "standard sieves" are holes drilled in sheet metal.
>> I can't believe that sports-field-maintainers would give a hoot!
I don't know, the fact sheet went into chemical composition , pH, and lots more. I think THIS company focuses on baseball fields and sports turf, but other companies selling expanded shale/clay target shopping mall flower planters and "green roofs".
Rick: Is there such a thing as screen with 40 wires to the inch? I don't see how there'd be any room for anything to fall through under those circumstances, even if the wires are really tiny! Maybe for straining consomme?
I think it analyzed at 3.6% passing through 20 mesh.
So 3.6 % smaller than 1/32" or 0.84 mm.
I think. It depends on whether the %s are "% retained by" or "% passing through".
And it matters a lot whether that is by weight or by # of grains. It almost has to be by weight, because counting grains would be expensive, even with electronics !
The dust & small stuff might even come from bigger grains rubbing against each other during bagging and transport. They are supposed to be durable, but they're also porous and must have bits near the surface that c an break off.
I went looking for sieve analyses of different producers of "light aggregate".
There seem to be mostly "too big" and "too fine" products.
Hydrock Medium might be interesting but I could find the size range.
Haydite Greenhouse Blend straddles the right size, but aren't ¼" too big and 1/16 too small?
Haydite Nursery Blend seems close but too coarse, primarily ⅛" to 3/8" particles sizes
Norlite see photo -
Intermediate is 62.5% bigger than 1/4"
Fine is 60% passing 16 mesh.
Haydite Greenhouse Blend is a specialized gradation of Haydite soil conditioner specifically designed for the demands of commercial greenhouse cultivation. Greenhouse blend consist primarily of 1/4"-1/16" particles sizes with nearly all dust and the very fine particles removed.
Haydite Nursery Blend is a specialized gradation of Haydite soil conditioner specifically designed for the demands of commercial nursery cultivation. Nursery blend consist primarily of 3/8"-1/8" particles sizes with nearly all dust and the very fine particles removed.
Al, I'm guessing you've been to all those websites years ago.
I don't mind if I lose half the Turface to screening -- I can find another use for the discarded portion. Al screens using insect screen, and only loses 1/3 of the bag. From what you've determined, Rick, one could screen using an 8 mesh (that is the smallest screen I currently have set up -- 8 wires to the inch, or 1/8th inch screening), and lose half the bag.
Happy, you touched on what I was thinking about while I was reading this (and, by the way, I can't WAIT 'til I get farther along in school to finally learn as much as you guys know about soils, Sheeesh!)... What do you guys do with the "discarded portions"? Where would it be useful?
I use the fines left over from screening Turface MVP in hypertufa projects, in raised beds, and to add water retention to the 5:1:1 mix for plants I know are going to grow fast & need lots of water (tomatoes,elephant ears, canna ...).
Al -- that gives me a great idea -- I was going to use a higher turface ratio for some plants (per you suggestion) that are water-hungry -- like 4:3:2 -- turface:bark:grit. Could I get away with using the discarded turface tiny pieces for this purpose?
One of the things that makes the gritty mix unique and so productive is the fact that it's made to specifically eliminate perched water. If you're going to reintroduce the fine particles that ensure there will be a PWT, you might just as well use something less expensive & easier to make - like the 5:1:1 mix or a peat-based bagged soil. IOW, it doesn't make any sense to go through the effort of making it unless you're going to take advantage of what it can offer. ;-)
For veggies, other short term plantings - like mixed display containers, and really fast growers that definitely appreciate a yearly repotting (as opposed to potting up), I use the 5:1:1 mix. For all my houseplants - including succulents, bonsai, and other perennial material (trees & shrubs are perennials, too), I use the gritty mix.
Al: So adding the Turface "extra fines" (for want of a better term) to the 5:1:1 mix is tolerable in the case of plants that are real water guzzlers and for which we'll change out the "soil" frequently, even though doing so may result in a perched water layer, but not in the case of the 1:1:1 "gritty" mix where we want maximum root support and further because we are aiming for long-term stability for that mix. Yes?
I mix discarded "fines" of almost any sort into my outdoor raised beds. They may be fine, but they are coarser than clay particles! (I wouldn't do that with sawdust or wood fibers - they go into a compost heap.
And a bed that sits on top of something that perks at all, has less concern with perched water than a container. I learned that from Al.
Almost any coarse discard can be used as a top-dress mulch.
If you already have decent soil, concrete paving stones have to be the fastest and easiest wall material.
You can make a 4 foot-wide bed by throwing in 5" of topsoil from a 2 foot band to the right, and a 2 foot band to the left. If you add another 5" of compost, manure, bark, grit or Turface, you have 10" of amended soil on top of whatever was there before, and an extra 5" of drainage into the sunken bands. If you broke up the surface and amended it 5" deep before adding soil from the sides, you might have a 15" root zone.
If your subsoil doesn't drain well, those side-bands ahd better slope or drain somewhere, so you can use them as walkways and still have dry feet.
I've already got very well amended soil in most of my beds, so prepping them wouldn't be necessary, just adding to them would be all I'd need to do. We sell many different sized pavers at work too, reasonably priced + my discount, so that is totally "do-able"! =)
... Now ya got me looking at those above-posted photos again.. which one is it? Or is it any of them?
Yeah, all I'd really have to do is wiggle the tip of my flat-nosed shovel into the soil a bit all around the border, just to be able to tuck the pavers in a bit, then do a little tamping with the 3-pound hammer (for level-ness), and I'm all set! =) We've got what we call "bluestone" pavers, in sizes ranging from 12" x 12" up to 24" x 24". Then there's the bricks... ;)
If you have enough good soil to fill a bed like that: ENVY ENVY ENVY!
I used to think that a raised bed was "just a big container", but Al convinced me otherwise. Unless it sits on solid rock, concrete, or un-pierced plastic , a bed that sits on soil is totally different from a large container with a bottom.
Even raw clay does perk "some". And that changes drainage a lot. Also, I suspect, that even if your outdoor bed starts out soil-less or "sterile", soil organisms soon colonize it.
This outdoor bed would start with about a 1 foot depth of mostly compost, with composted leaves and plain ol' hardwood mulch, and a bit of perlite thrown in for fun. ... Actually, nearly all of my beds would start out that way. There's hardly any old "existing" soil left in there, nearly no clay or rocks anymore, I've worked the heck out of those areas, and my back knows it. ;) There's TONS of fat happy worms in those beds. =)
Certainly Fred... (though, might I suggest a Dodge? heehee)... the new thread can be found Here: http://davesgarden.com/community/forums/t/1299621/ Thank you for asking, sometimes we get a little carried away with posting and don't pay attention to the numbers. =)