Vermiculite – An Ingredient in Some Hypertufa Recipes
and a Great Additive for Garden Soil
I get emails from time-to-time asking where to find vermiculite, which is mentioned as an ingredient in many hypertufa recipes, such as two that are provided in my article: Four Great Hypertufa Recipes. So I thought I’d provide some background information about different uses for vermiculite and how you can go about finding it in your area.
Vermiculite is used for many purposes: for horticultural use as explained below; industrial – used as an absorbent, an additive in textured paints, in brake linings, and for fiberglass reinforcement; in swimming pool installations – a great alternative to sand for the bottoms of vinyl-lined pools; and in construction applications – as an addition to concrete or plaster for enhanced insulation properties and fireproofing needs.
In our garden, horticultural-grade vermiculite has the excellent property of improving soil aeration while retaining the moisture and nutrients necessary to feed roots, cuttings, and seeds for faster growth. Vermiculite is clean, odorless, nontoxic, and sterile. It will not deteriorate or turn moldy or rot. Plus, the pH of vermiculite is essentially neutral so it doesn’t change the acidity or alkalinity of your soil. Another benefit to using it includes its ability to hold and make available to the growing plant ammonium, potassium, calcium and magnesium.
Faster, stronger root growth is normally experienced when vermiculite is mixed in with peat, composted bark, organic compost, and/or garden soil. If you do add in some vermiculite to your preferred garden soil mix, it’ll help retain air, plant food, and moisture and will also release these slowly to the plants. Because vermiculite is very light and easy to handle, it easily mixes with soil, peat, composted pine bark and other composted organic materials and fertilizers.
But What About Finding Vermiculite for Gardening Needs or as a Additive for a Hypertufa Recipe?
Ah … here comes a bit of a challenge for many of us – where to find the stuff? Usually, decent size bags of vermiculite can be found on the shelves of gardening or landscape centers. But, I couldn’t find any in gardening centers in the southern state I previously lived in. However, I do admit I didn’t try calling pool installation or concrete companies – many times you have to become more of a detective and turn to commercial sources to find it.
However, now that I’m living out west, I’ve found bags of vermiculite staring me in the face on the shelves of most gardening stores and nurseries. Strange … for sale in some states, and in others … none! I can’t give you a reason why availability can vary so much – that’ll take a bit of research on my part.
But if you’re determined to use vermiculite in a hypertufa recipe and can’t find it, then you can substitute perlite, which is normally readily available across the country in gardening and landscape centers. However, perlite is whiter and of a different consistency than vermiculite, but serves about the same purpose. But many hypertufa enthusiasts don’t like the stark whiteness of perlite, and prefer the color and light reflective qualities found in vermiculite.
So … if you’ve tried looking in all the gardening centers, and you’ve called local swimming pool installers and commercial concrete companies and still can’t find vermiculite in your area, then you’ve got at least these two options: 1) go online and buy it; or 2) investigate even further in your locale by doing an internet search for “vermiculite sources [your city and state]”. You’ll find many results (hopefully, some being local to you) that might lead you to a resource.
One last word of advice regarding the price of vermiculite – buyer beware. I’ve read over the years of prices for the same quantities in the same city to be quite far apart by many dollars! Do a little price investigation before you buy it.