Nematodes: A Natural Alternative to Pesticides

Along with summer comes grubs, chinch bugs and fleas to wreak havoc on your lawn. Forget typical insecticides — nematodes are naturally nifty. These microscopic worms attack other organisms in the soil.

It’s almost summer and beetle larvae (aka grubs), chinch bugs and fleas are on their way to damage your lawn. For those not wishing to use petroleum and chlorine-based insecticides on their landscape, there is an effective alternative: beneficial nematodes.

Beneficial nematodes are microscopic “worms” that attack other organisms in the soil. The nematodes are sold in your local nursery on blue sponges that are kept cool. You may also request them online and have them sent to you. I prefer my nematodes fresh.

Once you purchase your sponges, which are filled with about 1 million nematodes per sponge, immediately — or within 48 hours — place them in bucket of water and spray or sprinkle the mixture across the yard. Dusk is the best time of day for an application. One sponge will cover approximately 2,000-3,000 square feet of landscape. Nematodes move with soil moisture so water the area lightly before application, as well as one day after you apply the mixture.

Nematodes survive in the soil for many weeks, but they are tasty to other microorganisms, so I would replenish the population every 6-8 weeks from mid-April to mid-November.

Remember nematodes as an effective alternative to chemical insecticides. They are beneficial to you and your landscape, but not very beneficial to pests!

Picture of Mark Peterson
Mark Peterson
Mark A. Peterson was a conservation project coordinator for San Antonio Water System before retiring. With over 30 years of experience as an urban forester and arborist, Mark is probably the only person you know who actually prunes trees for fun. When not expounding on the benefits of trees and limited lawns, you're likely to find him hiking San Antonio's wilderness parks or expounding on the virtues of geography and history to his friends.
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