›› Margaret Hantiuk
I recently chatted with master composter, certified organic land care professional, and certified horticultural therapist David Greig, who has been “farming” red wriggler composting worms for over 25 years, in addition to teaching at Camosun College. These little workers (also called “tiger worms,” “brandling worms,” or more properly, Eisenia foetida) digest organic matter to produce a rich mixture of castings (worm poop) and undigested organic matter known as “vermicompost.” David had his product analyzed by Corvallis, Oregon’s EarthFort Lab, and was told it is the richest product they have tested for biological microorganisms.
As David explained, the first thing for gardeners to understand is the necessity of building the soil in order to have healthy plants. Throwing on chemicals or adding chemical fertilizers are short-term solutions that do not build the foundation of plant health—that is, to have a vital soil that is teeming with microorganisms. These tiny creatures form a vast network in healthy soils that not only feed plants, but also, by attaching to the plants’ hair-like root ends, create the symbiotic food delivery system. Chemicals and fertilizers directly and temporarily jolt a plant with a couple of nutrients, but they don’t build this delicate soil infrastructure that has been thousands of years in the making. “Build the biology and usually the chemicals needed will become available naturally,” he says.
Red wrigglers migrate to any compost heap or debris that is consistently moist, dark, and cool, with a neutral pH. They need lots of food as they are voracious eaters. Compost that is hot and really working won’t host red wrigglers—they cannot take the heat. A different kind of composting is required, with less coarse materials and a slower process. To make his vermicompost, David’s worm bins use coconut fibre and OMRI-certified peat moss. Where coarse, woody, debris that falls onto the floor is first composted by fungi, worm bins use microorganisms and less fungi, hence their value. And vermicompost is not high in nitrogen, so it will not burn plants.
This rich and crumbly vermicompost can be used in compost teas (add a handful to a pail of water that has been left standing for a day to release the chlorine), used as a foliar spray, or to sprinkle over the mulch around the plant. It can be mixed into the top of container plants, household pots, or greenhouse containers to add microorganisms (which purchased potting mixes lack). In the garden, it is best mixed into the topsoil so that the microorganisms can migrate easily into their new environs. Adding it to compost after it has turned can add more diversity to the precious microorganisms.
David makes his own potting soil with a mix of vermicompost, glacial rock dust, greensand, kelp meal, perlite, lime (calcium carbonate is best, with no magnesium), coconut fibre, and EM (Effective Micro-organisms, a product he buys from The Gardener’s Pantry). You can add any of these materials to your purchased mix.
Most worms here have been introduced—the common earthworm, for example, is from Europe—because most of North America has been glaciated. While the introduction of worms in the forest is a concern because they compete for food with native microorganisms, these mini-workers are a boon to urban gardeners where the natural ecosystem has been altered; we need to accelerate the building of healthy soil.
David says that the lifespan of his worms is 1 to 3 years. He doesn’t sell them, but does sell his vermicompost. Contact David at From Heaven to Earth Products at email@example.com.