I'm making my own potting soil from sifted leaf mold and perlite. However, I'd like to substitute sharp sand for perlite. One can easily find clean, horticultural sand at garden centers in England, but what about here in the United States? I've searched on Google, to no avail. Any help would be greatly appreciated! Kevin
Where does one buy horticultural "sharp" sand?
I've heard that a similar product (I don't think there's a product exclusively called 'horticultural sand' sold in the US) is sold at most home improvement stores under the name 'builders sand'.
Hope that helps!
You would be better served to use Turface or calcined DE. They won't compact and the larger particulate size will reduce what is sure to be more water retention than you want.
You would also be better off if you used crushed granite in 'starter' size, if you choose not to use the Turface or calcined DE.
The houseplant soil I grow in:
I love the crushed granite in "starter" size. I found it at the agricultural store (Blue Seal Feeds and Needs) here, and it is wonderful! I have used it to amend most of the media for my houseplants, and also for the cold-hardy cacti and succulent garden. I have learned that if you look in the water garden section of HD and Lowe's you can find the product which either is, or is close to, turface. I also add in just a bit of desert sand which I can find in the same stores, as well as True Value.
The soil in the picture above is extremely durable from a structural standpoint - it will not collapse and always retains excellent aeration. It is comprised of equal parts of Turface, uncomposted fir (or pine) bark, and crushed granite (grower size in this pic). There is also a little vermiculite in it, and a micronutrient source - Micromax. I've been using it for years and have seen nothing better so far. It stands head and shoulders above the bagged, peat-based soils.
Thanks for the advice, gang! Now, to annoy you with further questions!
Al - What is 'turface' and 'calcined DE'?
Nan - I have tried 'builder's sand' (from True Value) and it was difficult to work with -- it turned to mud when I added it to sifted soil and leaf mold.
mamsita - thanks for the tip on crushed granite. My only concern is that it might be too heavy. I will check this, however. I'm in Columbia County, NY and also have a Blue Seal Feeds and Needs nearby.
The crushed granite comes in different "sizes". You can either ask the staff or judge for yourself which might be the correct size for what you want to do. Are you just off the TSP?
Turface is calcined (baked in an extremely hot oven) clay, heated to the melting point so the tiny particles fuse together and it becomes ceramic-like. Turface is the tan particulates in the picture above. It has superb interior porosity, so it holds water well w/o allowing the soil to become saturated. It also holds nutrients well. Calcined DE (diatomaceous earth) is baked diatoms (tiny animal) skeletons and is physically much like Turface, but it has even better internal porosity and CEC (again, the nutrient-holding ability).
These products contribute tremendously to soil porosity, and because of their larger size, they help eliminate the perched water (saturated layer of soil at the bottom of the container) that virtually all peat-based soils come equipped with.
Here is a long discussion about houseplant soils from late '07. You may find it helpful.
Ask for 'Gran-I-Grit' brand in 'grower' size. It is most appropriate for the highest % of soils, but I sometimes use 'starter' size in some soils as well.
I am using the "starter". But keep in mind, I originally bought it to use as an amendment for my hardy C&S garden (outdoors) and just incorporated it into my mix for the houseplants. Love this stuff!
Mamasita - I'm in the town of Kinderhook. There is a Blue Seal nearby, in Chatham.
Tapla - Would you believe that I am already familiar with Gran-i-Grit? I use it in place of pebbles for my humidity trays. I will give this a try in my houseplant potting- medium experiment. Is the "grower-size" the smallest grade?
Al - Turface sounds similar to perlite (also heated at high temp. to produce porous granules). I enjoy reading your comments. Kevin
WG - I think 'starter' is the smallest size Gran-I-Grit packages, and it is smaller than 'grower' size.
Turface is different than perlite. It has lots of internal porosity - perlite has none, so Turface allows the soil to hold lots of water w/o the water clogging soil pores. Because the particles are larger than peat, it holds more air between the particles, but still holds readily available water internally. The beauty of a soil comprised of equal parts of Turface: granite: pine bark, is you can maintain a small organic component (the 1/3 bark - prevents compaction/soil collapse - greatly adds to soil's usable life) in the soil and 'adjust' the amounts of water the soil will hold by plus/minusing the Turface/grit. For example:
3 parts pine bark
4 parts Turface
2 parts granite
will make a soil that still has only a 1/3 organic component and holds lots of water, while a soil of:
3 parts pine bark
2 parts Turface
4 parts granite
will hold much less water & might be more appropriate for cacti & succulents.
The calcined DE (floor-dry from NAPA stores) is much closer to Turface than perlite. I prefer the Turface over the DE because it's pH is a little lower. Other than that fact, the DE is actually slightly superior to Turface in internal porosity and CEC (ability to hold nutrients).
Thanks to all of you. I'm off to purchase the various mediums discussed. I shall experiment with those I can find, and report back!
Well now............you all have just taught this old dog a few new tricks. My best stocked sources here are Lowe's and Wallmart. They however at this moment do not have what you sent me out looking for. Typical!!! We are not in an area that has huge lawn and garden centers. One horse and one wagon more or less brings us what we get to look at on our outlet shelves.
I shall call my brother in law and put him to work in NH. That at least is in granite country.
Find the Turface through the Turface locater: http://www.profileproducts.com/en/sports_fields/wheretobuy.htm or look for Profile Allsport at John Deere Landscaping dealers: http://www.johndeerelandscapes.com/storelocator/BullseyePro/search.asp?SearchSubmit=1&Admin=&country=US&ZipCode=&Radius=10&State=PA&ResultsPerPage=20&btnSearch=Search+By+State
Find the Gran-I-Grit crushed granite (grower size) At rural elevators/feed stores. Look in the online yellow pages under elevators near you and call. I've found it for many people in other states from right here in MI via the yellow pages.
Thanks...........my closest JohnDeere is two hours away. Chrushed granite may be in the form of chicken grits here, will check Monday. DE will work for me because our natural PH is 5 - 5.5. I can at least work towards a nicer potting medium with what we have discovered.
Yes, Doc, what I bought was chicken grit. Same stuff.
Son of a gun! I have been trying to locate granite for several years for the trace elements it has built in. I've even been pestering grave stone or grave marker places looking for dust. That in this area is not suitable due to other additives added in the processing of the granite markers. The counter top people have very little dust. It ends up in murky dirty water while they are wet cutting. They filter it as very wet mud and send that to the landfill. They were not interested in dern fool gardeners playing potty arm in their dumpster. Liability issues.
So here is granite right under my nose sold as chicken grits. I have to wonder if the dust of that passes through the bird and ends up in the poop.
Doc - when it comes to micro-nutrients and granite, size is everything. The large particles have such little surface area (and therefore such low solubility) compared to dust, that they wouldn't be effective as a source of trace elements. Sorry - same as trying to incorporate limestone gravel & expecting Ca & Mg from it - no go.
I use it just to aerate the heavier soils and potting mixes. I love the way it feels once added . I can let you know how the C&S did in the garden I put in last year. I used it to amend the soil in hopes that cold hardy cacti would survive our winters.
Al...........just to be arguementive a little bit.......the local Trout Unlimited organization and many other biological persons and institutions have sweetend up a sizable mine acid flow in a mountain stream by simply adding tons and tons of 1B and 2B limestone about eight years ago.
They succeded! Today the wild trout are numerous in that previously sick poisoned stream. I am reasonably sure the issue at hand was by no means cost effective if were your money and mine out of pocket. In a sense it was our money but the whole project has been and continues to be observed by biologists from all over the world. Based on what my simple mind can deduct it may continue to work for another twenty to fifty years. The mine acid is still running into the head waters. A half mile or so down stream they have clean pure mountain water ballanced. Would not the same apply to gardens in a very slow manor while improving the structure too? Certainly mineral dust would make the adjustments faster with proper use.
The sulfurous flow from the mine probably has a pH of 3.0-4.0, and under those conditions limestone is soluble. When we add lime to container soils, there are two fractions of activity. First is the reactive fraction - the limestone is reactive at the initially low pHs commonly seen in bark/peat based soils, which are usually
Al, reference your post 6323919 above; I'm gonna plant mostly cacti & succulents in the gritty mix and for my next batch will use the ratio mentioned there. Quick question from this mathematically-challenged gardener: for my 1-1-1 ratio already mixed up, how much more granite would be appropriate to add to achieve the "3-2-4" ratio?
3 parts 1:1:1
2 parts bark
1 part screened Turface MVP
3 parts grower grit
will give you a 3:2:4 ratio
You could probably just mix 1-2 parts of grit with 3 parts of 1:1:1, which is more like how I judge things, rather than doing all the measuring and calculating.
The greatest value of granit is it's trace mineral content. With a 1 - 1 - 1 mix already to go why would you wish to over fertilize cacti and succulents by raising the NPK? By doing so you could end up with some kind of fast growth and an unhealthy plant root enviroment. This in nature sets up an automatic response for the biology to kill the sick plant. It would seem to me that your 1 - 1 - 1 if accurately reported might be to much NPK allready. Cacti and succulents are nearly always found growing in extreme difficult environments. That is what the evolution in nature designed them to do. Most of my cacti and succulents are growing in sand with a tablespoon full of finished compost added to a four inch pot at the time of potting. Once every month or so excluding my winter months I water with one of my organic teas. I never add any man made NPK.
If you are wishing to force fast growth for market profits that would be a whole different consideration.
We're discussing soil ingredient ratios - not fertilizer. But - in container culture, we consider crushed granite inert & should not depend on it to supply any part of the plant's nutritional needs.
Whether you use a 1:1:1 ratio or a 3:1:2 ratio, or any other RATIO, plays little part in whether or not you are over-fertilizing. It's how you APPLY those fertilizers. The solution strength and intervals between applications that determine whether fertility levels (EC/TDS) are appropriate.
Sorry I melded into the discussion reading the numbers wrong. You may not figure on the value of trace minerals. That's OK. Never the less you will get that minute bonus when granit is used in the medium. And yes minerals and trace minerals are not considered fertilizer yet they are very important elements in any growing medium that is biologically sound. Of course they come from the use of numerous soil building elements. They may but certainly do not need to come from the use of granit.
I actually DO consider the value and availability of all the essential elements very carefully, but any of the granite particles we would be using in the soils we are talking about are simply too large in particle size to be considered a source of nutrition in containers (see my post #6365805 above). You may find ground granite (smaller than 200 mesh) of some value in mineral soils that are deficient in one or more of the elements contained within, but granite dust is not a good thing to add to container soils when micro-nutrients are so readily available in forms that do not affect drainage and aeration negatively.
In container culture, being 'biologically sound' is unimportant when compared to the same term applied to mineral (garden) soils. It appears that you're trying to bring the garden to container culture, and they are distinctly different types of husbandry. On a scale of 1-10, with 1 being growing in gardens/beds and 10 being hydroponics, conventional container culture is probably a 7 or 8. What works well in the garden is often best left there because very frequently garden practices and beliefs clash with the ability to maintain plants at peak vitality in containers - including and often especially houseplants.
Sorry for the detour TG. Are you all squared away with your soil questions?
Yes, thanks to you, Al. I'm all for the "easy" instead of more measuring and/or calculating! mg