Vermiculite alternative for square foot gardening? (2023 Update)

Hi all,

I'm a complete newbie when it comes to gardening and am trying to start a plot using the concepts of

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He suggests a mixture of 1/3 peat moss, 1/3 coarse vermiculite and 1/3 compost. Problem is I can't find the vermiculite and the guy at our local garden center says it's because it's now illegal. I did some research on this group and see that it's been discussed extensively but couldn't find any suggested alternatives. What else would you put into this mixture if you couldn't find vermiculite? In case it matters, I'm in zone 6a and am planning on planting tomatoes, peppers, beets, arugula, basil, parsley, peas and beans.

Thanks for any advice you can offer!

LauraJ

Reply to
Laura J
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I've always found perlite to be useful in applications similar to this.

BTW vermiculite is NOT ILLEGAL but it seems that some of the ill-informed have decided that since vermiculite from one location in the US had some asbestos in it that all vermiculite must be dangerous and that the sky is falling and refuse to have anything to do with it no matter the source. If you can find a vendor with the intelligence to know the difference you should have no trouble buying vermiculite.

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Reply to
John McGaw

I was also told that vermiculite was illegal I then found it at another garden store. It's also sold at builders supply stores that sell to plasterers

Reply to
H Hornblower

I agree about the perlite. But asbestus litigation is a growing industry, and with number of companies with deep pockets and actual liability concerns dwindling, the lawyers are going after anyone who can even spell "asbestus". I wouldn't sell vermiculite, even from a certified asbestus free supplier; I don't an unscrupulous lawyer breathing down my neck 20 years from now when some gardener (who may or may not have been my customer) gets mesothelioma and starts suing garden centers that once-upon-a-time sold vermiculite.

Best regards, Bob

Reply to
zxcvbob

Okay, from my research into this vermiculite problem, it's the stuff they get from Africa, not our local vermiculite which is the problem. However, lava sand is a much more effective product, if you can find it.

Reply to
escapee

Okay, so it seems I just need to find the stuff somewhere. One problem I'm having is that every source seems to sell it in a different measure, so pounds one place, quarts or liters somewhere else. I'm looking for 3 or 4 cubic feet. Does anyone know how many pounds of vermiculite is in a cubic foot? I think 4 cubic feet comes to just over 100 quarts which is a heck of a lot of those little 8 quart bags they have at the one local store I found which carries vermiculite. Does anyone have a trusty online source they've used?

For the record, I'm planning on a 5x3 8" tall raised bed. I've bought 3.8 cubic feet of peat moss and I'm hoping to get about the same amount of compost from the city (Boston) along with slightly less vermiculite wherever I can find (and afford) it. Does this sound about right or am I totally barking up the wrong tree? If I don't end up finding the vermiculite, I was thinking of suplementing with something else (some kind of soil?) and just throwing in a small amount of the perlite. What do you think?

Thanks for all your advice!

LauraJ

Reply to
Laura J

See my potting mix recipe at . The necessary texture -- drainage, aeration, moisture availability -- is provided by the sand and peat. You only need a little compost (real, not some commercial potting mix) to provide the friendly soil bacteria that release the nutrients.

Reply to
David Ross

Reply to
escapee

Another question about square foot gardening; I noticed that watering is very crucial as there is no place to the excess water to go. Does one have to cover the plants when it rains to prevent root rot?

Olushola

Reply to
Olushola

Skip the Mell soils and follow this link

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Lots of great mixes without Vermiculite

Buy vermiculite from a Home Depot and save lots of $$$$ if you MUST use it Acts of creation are ordinarily reserved for gods and poets. To plant a pine, one need only own a shovel.

-- Aldo Leopold

Reply to
Tom Jaszewski

Water drains out the bottom. I use a raised bed, works great, and the water drains just fine. I guess it could be a problem if you're lining the bottom, but why do that?

Swyck

Reply to
Swyck

one need only own a shovel.

I don't use vermiculite, I use crushed or decomposed granite sand in my mixes.

Reply to
escapee

The raised bed seems to be a better way to go. However, if one lives in an apartment, then I can see the value of lining the bottom.

Olushola

Reply to
Olushola

So is the vermiculte only used to "lighten" the mix or does it add some specific nutrient that might be missing if I use sand or whatever? Where do you get decomposed granite sand? Is that something that is sold specifically for gardening or can I get it at any old hardware store?

Thanks again, LauraJ

pine, one need only own a shovel.

Reply to
Laura J

Vermiculite is inert, has no nutritive value to speak of and is used merely by the greenhouse industry as a potting medium and seed germination product. It is used because it is very lightweight and deliveries are easier and trucks can haul more.

Compost is the nutritive value in soil structure, not the hard substances like sands of any kind. I buy lavasand or crushed or decomposed granite in Home Depot or Lowes. I don't know where you live or what your local retailers sell, which is why plain play sand is also good to take up space and help drainage. I don't know anyone who uses vermiculite in the soil, just in pots.

Reply to
escapee

Vermiculite is a mica-like mineral. When heated, the laminae break apart and the mineral expands, which makes it light and also makes it able to hold water. The primary value in growing media is its water holding capacity, coupled with improved drainage. That sounds contradictory, but it's not. The water is held in the vermiculite particles, but the particles are large, creating spaces in the medium between the particles through which excess water can travel for drainage. Since roots need both water and air, vermiculite is a valuable addition for starting plants. I believe the basic composition is related to silica, so it has no significant nutritive qualities.

As a mineral, it is extracted from mines.

Reply to
Dwight Sipler

replying to Laura J, M Casey wrote: In addition to potential downside of using vermiculite, there is the fact that peat moss harvesting is environmentally unsustainable. Even though peatlands occupy only 3% of the Earth's surface, they store a third of the world?s soil carbon, twice as much as forests, and when they are harvested, carbon dioxide is released, the major greenhouse gas driving climate change. Many people recommend coconut coir as an environmentally friendly alternative to peat moss.

Reply to
M Casey

Is coconut coir as absorbent as peat moss? Also, why are you out here posting on a discussion from 15 years ago? I thought I was the only weird one out here reading this stuff.

Reply to
athenamorris

Vermiculite Alternatives Finely ground pine bark, also called "pine fines," is a principal ingredient of most potting mixes. As an alternative to vermiculite, pine fines also offer water-retentive qualities, especially with smaller particle sizes. Cotton gin waste includes gin leavings, such as stems, leaves and hulls. Cotton gin compost renders these waste products into a viable alternative to vermiculite, also because of its ability to increase water-holding qualities in mixes. Resembling sphagnum peat moss, coir is the finished product of ground coconut husks. The University of Arkansas Cooperative Extension Service reports that coir can retain up to nine times its weight in water.

Reply to
Frank H

After the Libby Montana mine was closed down there was another source found in the Carolinas which has since been depleted. Most of the vermiculite we have been using has been imported from Algeria but because of the political unrest there imports have been curtailed. Unless a new source is found there will be no more vermiculite or a very limited supply which will be more expensive.

Reply to
pls

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