A Discussion about Houseplant Soils (long post)

North Augusta, ON

I have some succulents potted in a mix that is one part soil and one part grit. I find the water goes right through. Does this mix do that? I'm thinking it wouldn't work for me cause all my plants are hanging. Might be a tad messy :)))

Bay City, MI(Zone 6a)

Yes - the water percolates freely through the soil about as fast as you can apply it - a beautiful thing. ;o) This is where you make a choice or compromise. If you limit yourself to what you presently grow in because it's convenient, you necessarily accept all the limitations of that choice. I'm only here to share the benefits of a well-aerated and free draining soil, to draw contrast between these soils and what comes off the shelf, and to help those interested in learning how to build a soil that will improve plant vitality and ease the burden of problems associated with more traditional soils. For you, it may not be worth it to carry the container to a sink or put other methods in place that would resolve what really doesn't seem to be an insurmountable problem, but for me, and perhaps others, the promise of improved plant performance will be worth what little extra effort might be required.

Al

North Augusta, ON

fair enough...can you come up with a soil that would meet me half way :))

Plenty of aeration, happy, healthy plants, but less water on the carpet?

Taft, TX(Zone 9a)

Tapla,
I am sooo excited. Today I called Southwest Fertilizer in Houston which is the best of the best in stores for any kind of soil or fertilizer. I asked him first what the value of Turface was and he said exactly what you did. He started explaining and all of a sudden it finally made sense to me. (I am pretty dense and stubborn) You have tried so hard to help us understand the value of the right soil compostion.

Then I asked him what he would want to sell me for a soil for all my outside pots using Turface. He suggested a part of a loamy sand top soil , one part sheep manure and then as much Turface as I need for aeration , etc. (he compared it to several things...one being perlite except that Turface doesn't break down.

I can hardly wait to make a trip to Houston and get what I need for both inside and outside and give it a whirl this spring as I start repotting. The end door is open and the sun is coming in.

You are just too nice to care about the rest of us and we do greatly appreciate your help.

Take a look at some of my plants on the front porch which is wrapped in poly which doesn't have good light transmission but is better for the plants with good circulation on days when the sun is shining. Tonight will be in the 30's but I close the doors about right now for the night.

The plants fell in love with the fertilizer of 12-4-8. Let me show you a few as I am shocked in the middle of winter that they look this good outside.

Thumbnail by gessiegail
Taft, TX(Zone 9a)

a big splash of sun on the brugs and Ginger

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Taft, TX(Zone 9a)

A little bit of everything that got a dose of the 12-4-8

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Taft, TX(Zone 9a)

the ivy on the end is growing like it is summer!

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Taft, TX(Zone 9a)

Look at this philo with the dracena to the left.

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Taft, TX(Zone 9a)

My front porch is turning out to be a good winter over place. Even the impatiens is happy with its' new food.

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Taft, TX(Zone 9a)

The caricature plants don't even know it is winter.
(The begonias on the table do know though...lol)

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Taft, TX(Zone 9a)

Hoya baskets are happy with their food! Thanks to you, Tapla

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Taft, TX(Zone 9a)

i won't bore you all anymore as I have many more photos and I am so pleased to see plants this way in December.
One last shot of an Amaranthus and another kind of caricature plant

Thumbnail by gessiegail
Bay City, MI(Zone 6a)

Gail - I really do like to feel like I'm helping, and you offer kind words, but let's slow down a little. I cannot take ANY credit for how your plants look. All I have suggested that you have implemented so far is that the 12-4-8 is an excellent fertilizer for houseplants, but your plants have done little growing in the few days that you've used it, so the fertilizer has nothing to do with any major change in growth, so no credit to me there, either.

It appears that you're sold on a mix of loam (topsoil), manure & Turface, which is your choice, but I've spoken strongly against both topsoil and manure in container soils, outlining the reasons why, and trying to offer some guidance in what makes a good soil, so I somehow get the feeling that you're not even listening to the conversations we've had or have simply decided to take another direction. I've seen other evidence in your posts that tell me you skipped right over extremely important information, so as much as I'd love to help you, I'm not sure I can.

If we can, let's try to keep the thread focused on 'Container Soils' for houseplants and keep photos to a minimum unless they relate to the subject of the thread? This will make it easier for those who might arrive at this thread later, by eliminating the burden of sorting through so large a number of posts that lack topic-relevant information. I'm very happy to continue answering any of your questions I find myself able to, or engage in conversation that will lead to further dissemination of information about soils. I hope that sounds reasonable to you. ;o)

Al

Taft, TX(Zone 9a)

Sorry that I extended the thread to mean outside soils, too.

I don't have enough houseplants except gesneriads to be participating in this discussion. I thought (wrongly so) that you were advocating the same soil basically as both indoor and outdoor soil.

Sorry about the pics but the fertilizer did change the appearance.
I agree I won't post anything else, but I will read and reread why the ingredients need to be exactly as you posted. I was wrongly thinking that there would be some improvisions as long as the Turface was used.

Bay City, MI(Zone 6a)

Oh Jeez - now you have me feeling bad, Gail. If you have even 1 houseplant, you have enough to be participating in the discussion and are very welcome. ;o)

The gritty soil mix can be used to grow practically anything in, and if you don't think it will suit your purposes, it can be modified as you see fit. There is nothing rigid or carved in stone about building soils. It's just that I'm advocating a stable soil that guarantees aeration, drainage, and long serviceability. Topsoil and manure are the antithesis of what I'm advocating as ingredients. I didn't want to appear like I wished to argue with your choices, and I had already carefully outlined why I argue against topsoil and manure, so rather than repeat myself several times, I thought it was clear you were headed in a different direction.

I think that if you do read carefully through the beginning of this thread again so you understand the principles clearly, and even perhaps read this http://davesgarden.com/community/forums/t/719569/ and ask any questions that come to mind there, you'll have the understanding of the relationship between the ingredients (air/water/soil components) that go into a soil.

I'm MORE than happy to answer any questions you have that are focused on soils or closely related subjects like nutrients. There is plenty of room to improvise, even though I think I've worked out a basic mix that anyone can duplicate easily and be successful with.

In a bonsai workshop I attended that was lead by Mr. Ben Oki, a master who was in part responsible for helping to bring bonsai to the west, Mr. Oki admonished the participants, "First you must know the rules - only then, can you break them." If you do yourself the favor of learning the things I wrote down in this and the other thread I linked to, and learn where to find a few simple ingredients, you'll not need my advice - ever again. You'll know all you need to know about the physical aspects of building a soil from whatever you can find with the confidence that it will perform well before you ever set a plant in it. I promise you that. The rest is up to (((you))), Gail. I've already helped hundreds of people, including many professional growers and even the city of Paris, France develop soils to suit their needs. It's little additional effort to help you.

So what's your next question?

Al

Taft, TX(Zone 9a)

Well, I feel worse than you for heading off in a different direction! My main question is, the recipe that you have will be good for inside or outside? I think I got confused when Lin asked about using sand and you said that was ok. If your recipe is only for inside the house, are you recommending that we make up that soil? And then improvise for the outside?

***edited to say that a fellow DGer asked me to pick up the trace elements when I go to Houston to Southwest Fertilizer for her. I don't have any fertilizers which don't have trace elements in them. What do I need to know about this as I don't understand why she wants to use them in her mix. Thanks



This message was edited Dec 27, 2007 10:45 AM

Dublin, CA(Zone 9a)

Al's got a couple great threads on the Container Gardening forum with recipes for outdoor container soils, what he was talking about here is for houseplants.

Taft, TX(Zone 9a)

thanks, ecrane. I think I am panicked about all my hoyas as I overwatered and the temps outside have not been as warm as I had wished for.
Thank you, Al and again, thanks for the recipe, ecrane.

(Zone 1)

Al: Do you by any chance have a book or some sort of publication where you have compiled all this great information regarding soil and water?? It sure would be nice to purchase such a book to have for reference to read and re-read.I hate jumping back and forth through these different links to different threads. I always seem to lose my place and get confused. And, I'm so bad ... I will book mark a specific site but then have so many bookmarks to go through to find something that I usually give up. I am lazy, what can I say? I really would love to have a publication right here on my bookshelf that I could refer back to time and again! If you haven't already done something like this, I really hope you will consider it! It's only $5 to place an ad in classifieds here on DG and I bet your book/articles would sell mighty quickly.

Bay City, MI(Zone 6a)

Gail - It would be really easy to make the case that there are no such organisms as houseplants. There are only outdoor plants that will tolerate indoor conditions to varying degrees. Right? ;o) From that thought, it's easy to extrapolate that there is no real difference between indoor and outdoor soils. Personally, I tend to draw some delineation between how I use the soils when deciding on how I build them. For houseplants and other perennial plantings that may remain in the same soil for more than a season or two, I always use a soil with a high (2/3 or more) mineral content, like the gritty mix. For the "pretty stuff" I decorate the garden & house with - mainly annual plantings, or for veggies and other short-term plantings, I use the other mix with bark:peat:perlite as the primary components at around a 5:1:1 or 2 ratio. After a season or two, long after a peaty blend would have collapsed, I simply turn the soil into the compost pile or garden/beds. Does that clear anything up for you?

I don't think I suggested anyone use sand in a container soil unless the "sand" is comprised of uniform and large particulates - 1/2 BB size to BB size. Remember - we're protecting aeration in our soils and fine particulates destroy aeration. That's why I suggest we leave out worm castings, topsoil, compost, sand, manure, and anything else that breaks down quickly or clogs micropores.

Nutrients: The essential nonmineral elements are: Hydrogen, oxygen, and carbon, and they come from the air and water. The essential mineral elements are: Nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, boron, chlorine, iron, manganese, zinc, copper, molybdenum, and nickel. Of this list N, K, Ca, Mg, P, and S, are called macronutrients, and the micronutrients are: Cl, Fe, B, Mn, Zn, Cu, Mo, and Ni. All of these mineral nutrients must be present in the soil water solution at all times for the plant to grow properly and many may not be included in our fertilizer. This means they must be present in the soil particles, or we must supply them. Knowledgeable container growers usually seek out sources of micronutrients to prevent deficiency symptoms. There are many ways to deliver the micronutrients, but I prefer the nonsoluble product 'Micromax' for incorporation in new soils, or 'STEM' as a soluble supplement I add to fertilizer solutions for established plantings. Others may be able to offer suggestions for products easier for you to find ...

Lin - Thanks for the compliment, but no book in sight. Does helping other's with their books/articles count?

Al






Taft, TX(Zone 9a)

Yes, you need to charge for your time! I am serious. We can think of something to do for you.

I am beginning to get a grip on this ( a little). I read your information on the container forum.
(I do know that thread is about houseplants but I have also read your response about indoor and outdoor mixes)

The mix I found makes great sense to me with pine bark, peat, perlite , maybe lime, 2 cups CRF and the micro-nutrient powder and I know where to get all these ingredients. Would you explain why we don't necessarily need Turface or a smiliar product (or does perlite take the place of Turface for the pretty pots outside)?

You do, though, seem to prefer the gritty mix I gather .

Thanks for your patience.

Bay City, MI(Zone 6a)

I do prefer the gritty mix because it is soo stable & long lasting. It virtually guarantees great aeration for much longer than it will take a plant to outgrow almost any container, so soil collapse is never a concern of mine. It costs a little more to make though. Since I go through somewhere around 200 gallons of soil in a year's time, I choose not to use the gritty mix all the time, even if it's better in the long haul (not everything is grown for the long haul).

How the gritty mix works is like this: The pine bark is a very inexpensive and long-lasting ingredient that has similar properties to peat, but insures better aeration and lasts much longer. The mineral components of Turface and Granite are added & subtracted to adjust water holding ability. Add more Turface & reduce the granite & the soil holds more water - for a longer interval between watering. Reduce Turface & add more granite & the soil retains less water. Turface is roughly equivalent to perlite, & crushed granite is roughly equivalent to very coarse (1/2 BB size) sand, but both Turface and granite are much better at their jobs than their counterparts. Also, there is some consistency in particle size and the particles are larger with Turface & granite, so drainage & aeration are much better.

Remember - garden soils are more than 90% mineral content, so the 2/3 mineral content soil is STILL very rich by garden standards and plants thrive in it because of its ability to hold air. All you need to do is institute a favorable nutrition regimen (you need to do that with ANY container planting anyway) and keep the plant watered. Good light and temp ranges are needed too, but that goes w/o saying.

Al

Taft, TX(Zone 9a)

I can't thank you enough! I am planning on repotting every plant I have and i think I will start with the cane begonias.

You were really helpful in that last discussion about more/less Turface and granite depending on the plant material. (And I do now finally understand that plants which I repot regularly can use some peat) Now I just need to locate Micromax. I think I will use the gritty mix on everything except tropicals. Am I ready to start repotting, Al? I can use the gritty mix on all my succulents, including all the hoya baskets, bougainvilleas, plumbago, duranta, jasmines, etc. in pots.

Would tropicals like begonias, hibiscus, plumerias, brugs, etc. benefit from using your peat mix or just use the gritty mix for everything? I just want to double check even though you did say I could use the gritty mix for everything if I choose.

I have printed up every thing that you have said plus all the recipes on both forums.
Who knows? I might be able to find everything I need around here at some of the feed stores and nurseries.

again, I am grateful for your advice and I am ready to go I think!

Brownsville, KY(Zone 6a)

Al,
Could one substitute pieces of broken clay pots in lieu of turface in the gritty mix? Would the irregular shard sizes or sharp edges be harmful to roots?

Shirley

P.S. I did call Profile Corp. and learned that there are a few landscaping businesses in Kentucky that carry it under the name of Turface All Sport.

Bay City, MI(Zone 6a)

No, Shirley ..... if you had to do that, I think you'd be better off to use a bark:peat:perlite mix. You want something that's both stable & porous. Turface, Haydite, Play Ball, and small pumice (lava rock) in that 1/16 to 1/8 inch size fits the bill perfectly.

Uniformity of particle sizes is very important in determining drainage and porosity. When I give talks, I often take a half gallon container that's "full" of boulder size marbles. To the "full" 1/2 gallon container, I can easily add a quart of BBs. So now, I've put 3 quarts of material in a 2 quart container - right? I'm not done yet. I can STILL add another quart of fine sand to the mix, making it 4 quarts of material in a 2 quart container. And - if you think I'm done - you're wrong. I can take almost another quart of water & add it to the container, making it almost 5 quarts in a 2 quart container. If you imagine the large airspaces between to big marbles, you can see how mixing BBs ans sand with the larger particles robs air space? The same thing happens when you add sand, compost, worm castings, or other fine particulates of various sizes to container soils.

Gail - Either mix will work fine, but the gritty mix will work better, primarily because it will last longer. It's a better choice for perennial plantings (practically speaking, all houseplants are perennials).

Al

Taft, TX(Zone 9a)

I am going for the gritty mix altogether including houseplants! This is so exciting to know that my plants will drain. I spent 4 hours yesterday sitting on the ground outside drilling holes in as many containers as I could get that were too wet and wouldn't drain.

gail

***edited to say you better be thinking where you would like a gift certificate for giving me such invaluable advice and I do love to water my plants!

This message was edited Dec 28, 2007 10:35 AM

Bay City, MI(Zone 6a)

Whether 1 or 100 drain holes in a container bottom, it won't make the water drain from the saturated layer of soil at the bottom of your containers. It's physically impossible - but, you can make it drain by adding a single wick through the drain hole and allowing it to hang below the bottom of the container. This "fools" the water into "thinking" the container is deeper than it really is. The water moves down the wick, dripping from the end & pulling water from the container as it drips.

Easy experiment to prove the value of a wick in removing extra water from soils:

Fill a Dixie Cup with soggy, saturated soil, then poke a hole in the bottom & wait until it stops draining. When draining has stopped, insert a toothpick in the hole or even just touch it to the soil through the drain hole & see how much additional water drains from the soil.

Al

Taft, TX(Zone 9a)

Wow! I am sitting here with a #36 poly string or panty hose.........I will get wicks going on each pot! Thanks for that information.
gail

Brownsville, KY(Zone 6a)

Al,
Thanks for the feedback on clay pot shards. I will omit them from my mix.

I am concerned about the 'mini' pine bark nuggets I purchased. They are far from being 'mini' in size, and there is nothing consistent about them. Sizes of pieces range from small to large. Today I soaked the entire bag of bark in some fish emulsion with a few drops of SuperThrive to soften it up before breaking the larger pieces into smaller ones. I also tossed out a lot of wood chunks mixed in with the bark. Is there any kind of standard or grading scale used by the companies that bag and sell bark?

How will drainage be affected by having different sizes of bark present in the mix? There's no way I would use some of the larger bark pieces I found in a mix for plants growing in smaller pots (4" or less).

Shirley

Bay City, MI(Zone 6a)

Size is important - see the first two pictures in this thread for appropriate sized bark. If you can't find what you see in the pictures, or partially composted bark, which will be smaller still and slightly decomposed - wait until you can find something appropriate and keep looking. You guys need to be patient and adopt the idea that you want to understand why these materials work so well together & then commit to the effort it takes to find them or a very close alternative. I promise that once you settle on a free-draining and durable soil you can duplicate over and over, it will pay big dividends in your abilities to keep plants happy.

See partially composted bark at the top of the picture. It's also ideal. The pine bark at the left is too large & the fir bark at the right is borderline too large.

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Taft, TX(Zone 9a)

Hello Shirley!
I am waiting for the answer to your question, too. I wanted to ask Al what do I ask for in size for both the pine bark and the crushed granite.

I have wicked a big hoya and you would not believe how much water is filling a bowl already. I am doing the happy dance just to find out what to do with these soggy plants until I can repot in spring. Will have a picture to show tomorrow.
gail

*******edited to say, 'thanks, Al'. Now I know the proper size.

This message was edited Dec 28, 2007 10:07 PM

Brownsville, KY(Zone 6a)

Al.
I really like the look of the partially decomposed bark. I'll keep looking!

Thanks again,

Shirley

Waterville, VT(Zone 4b)

Al,

Does the bark have to be pine or can it also be Fir or Hemlock?

Doug

Taft, TX(Zone 9a)

I hope it is appropriate for me to show these 3 pictures of wicking a hoya basket with #36 poly string from the fishing dept. of Walmart. I am simply amazed as water is still coming down this morning.

First is a picture of the strings in the hanging basket from the bottom and close to the bottom on the side.

Thumbnail by gessiegail
Taft, TX(Zone 9a)

bowl of water that has come from the wicks of the hoya. This is a new bowl this morning.

Thumbnail by gessiegail
Taft, TX(Zone 9a)

If you look closely for the drop of water at the end of the strings, you can see how effective Al's way of getting that water to come on out of the soggy plant.

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Bay City, MI(Zone 6a)

Doug - I've used pine, fir, and hemlock bark interchangeably with equally good results.

Gail - the wicks needn't be so long - an inch or two below the drain hole is sufficient, though there's no disadvantage in leaving them long.

Al

Taft, TX(Zone 9a)

Thanks for the information, Al. That is good to know so it won't be such an unsightly appearance on the porch when I wick all my plants. When I get all the ingredients ready I will use the gritty mix for everything.

Plano, TX

al--i may have missed it but does the wicking string need to be a certain kind? and i am hoping you can just poke it into the holes at the bottom rather than needing to do so when you pot the plant? it seems like such a good idea and especially after reading todays article about plants getting too much water---thanks

Bay City, MI(Zone 6a)

It's less important for a wick that drains the soil to be as absorptive as one you use to water the soil, but it still is helpful to use anything that is able to draw water several inches upward from a water source's surface. Strips of man-made chamois works very well, as do those flat strips cut from rayon mops (both 100% rayon), but since rayon is made of cellulose, it will need to be replaced occasionally. Sometimes old shoelaces work very well, & I really like the nylon string ties that some onion and citrus mesh bags are tied shut with because they never rot, yet wick water very well.

You're right - you can simply push a wick up into the soil through the drain hole. Usually, just folding it over the blade tip of a straight slot screwdriver and pushing it into the soil works perfectly.

Al

This message was edited Jan 1, 2008 7:58 PM

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