By Sean James
The use of bio-controls—the use of ‘good’ living things to control ‘bad’ living things—is a new and fascinating realm of lawn care. If your yard is infested with white grubs (e.g. Japanese beetles, European Chafers and May/June beetles), European craneflies (leatherjackets) or other pests that spend part of their life under the soil, nematodes can provide excellent control. These microscopic worms hunt through the soil and eat the pests from the inside out—gruesome, but very effective. While these creatures sound frightening, they are actually very safe. Nematodes will only attack soil-borne insect larvae and pupae; they can not affect children, pets or birds.
Research the type of pest you have and consult with a garden centre or a company that distributes nematodes to determine the best time to apply the nematodes. When it comes time to let the nematodes loose, a few simple tricks, in addition to the manufacturer’s instructions, can help make the application process a lot smoother.
Nematodes are very sensitive to sunlight and are best applied just before a heavy rainstorm, not only because of the cloud cover, but also because they must be watered into the soil immediately. Nematodes can also be applied in the early morning or late evening, providing you are able to water them with a sprinkler or irrigation system right after they are applied.
A package of nematodes typically contains a sponge with a beige ‘spot’ on it. This spot typically comprises roughly 10,000,000 nematodes, depending on the type and formulation. The nematodes are then mixed with a given quantity of water, as per the directions (typically about 4 L [1 gal]). As you apply them, the water must be continuously stirred to ensure the nematodes are evenly spread throughout the solution. Avoid using chlorinated water; if that is all that’s available to you, let the water sit overnight prior to mixing, to allow the chlorine to evaporate. Collected rainwater is also an excellent and environmentally conscious alternative.
This article is part 7 of 8 from our blog series “Keeping it Green: Beautiful turf can be sustainable, too“.