Vermiculite can be used effectively as a mulch for some types of plants, including roses and tomato plants. Vermiculite can be used effectively as a mulch for some types of plants, including roses and tomato plants. Like perlite, vermiculite is a naturally occurring mineral that expands when heated. The curly, worm-like appearance is responsible for its name, which comes from the Latin vermiculus, meaning "insect larva" (ultimately from the Latin vermis, meaning "worm").
Vermiculite is formed by weathering or hydrothermal alteration of biotite or phlogopite. Exfoliation occurs when the mineral is heated sufficiently, and commercial furnaces can routinely produce this effect. If you are sensitive to dust or plan to handle large amounts of perlite or vermiculite in the garden, you can mitigate any problems by wearing a dust mask or covering your nose and mouth with a handkerchief. But, and this is an important but, vermiculite is more compressible and less porous than perlite, giving it a greater water-holding capacity when used as a planting medium.
If you are sensitive to dust or plan to handle large amounts of perlite or vermiculite in the garden, you can mitigate any problems by wearing a dust mask or covering your nose and mouth with a handkerchief. Vermiculite is a hydrophilic phyllosilicate mineral that undergoes significant expansion when heated.
What is vermiculite used for?
Vermiculite helps aerate the soil while retaining water and nutrients, which it then releases over time. Vermiculite is a naturally occurring mineral (magnesium-aluminum-iron silicate) that is mined in several countries around the world, including the USA and South Africa. It retains some water, but also air on the surface of the pellets in all hidden recesses. A mixture containing about 30 % vermiculite is ideal for pricking out and planting seedlings.
More information If you are facing these problems in your garden, adding vermiculite to the soil is an excellent option. Because vermiculite acts like a sponge and absorbs more water than perlite, it doesn't aerate the soil as much. For plants that need to overwinter indoors, vermiculite offers an easy storage solution that will keep bulbs or root systems at their best.
What are the dangers of vermiculite?
As long as this type of vermiculite-based insulation remains intact behind walls or in attic spaces and is not airborne, it should not be a cause for concern. If you discover dangerous vermiculite in your client's home, your first question may be about removal. Unfortunately, the same mine was abundant in asbestos ore, a particularly dangerous type of asbestos known as amphibole asbestos or tremolite. Vermiculite mined near Libby, Montana, which accounted for more than half of the world's vermiculite production between 1925 and 1990, was contaminated with asbestos and asbestos-like fibers.
This is a more dangerous type than the chrysotile asbestos that was used in many other household products. Unfortunately, an estimated 75 percent of it came from Libby, Montana, where it was generally contaminated with toxic amphibole asbestos. If you don't go into your attic, handle or disturb the insulation, you probably won't be exposed to asbestos fibers from vermiculite insulation.
Is vermiculite safe now?
Vermiculite has a light brown or golden pebbly appearance and homes built before 1995 are at greater risk. If you absolutely must enter your attic and it contains vermiculite insulation, you should limit the number of trips you make and shorten the duration of those trips to help limit your potential exposure. When subjected to heat, vermiculite has the unusual property of expanding into worm-like chunks (the name vermiculite derives from the Latin 'vermiculare' - to breed worms). Vermiculite that is accompanied by a large amount of dust probably has residual asbestos in its contents and should be used with caution.
The EPA (Environmental Protection Agency) recommends that if you have vermiculite, it is best to assume it contains asbestos and leave it alone. For professional home inspectors, it may only be a matter of time before they are confronted with this material.
