Many insect garden pests can be eliminated with treatments of diatomaceous earth (D.E.). It serves as a barrier to slugs, snails, thrips, ants, earwigs, fleas, ticks, spider mites, flea beetles and many others. D.E. is even a deterrent for bedbugs.
What is Diatomaceous Earth?
Diatomaceous earth is made up of 33% silicon, 19% calcium, 5% sodium, 3% magnesium, 2% iron and has trace minerals like boron, copper, zirconium, titanium, and manganese. It's a natural compound from diatoms mined from deposits of diatomite. Diatoms are tiny single cell algae-like plants, that have been on this earth longer than man. Their microscopic skeleton remains have build up over the last 30 million years, to thick deposits of chalky diatomite.
Agriculture designated diatomaceous earth is ground to a fine powder, but to the tiny insect pests in the garden like the spider mite, this powder is sharp enough to cut into soft-bodied pests, causing dehydration and death. Earthworms are not harmed, however.
How to Use Diatomaceous Earth
Diatomaceous earth can be applied to the garden to eliminate insect pests dry or sprayed on as a slurry, which will dry without reducing its effect. Apply in the evening, after watering. Starting from the ground, apply to the stems and leaves of the plant. Pay extra attention to the underside of the leaves. As many garden insect pests winter in the soil under garden debris, fall garden cleanup for infested areas of the garden should include a dusting of D.E. after foliage and debris have been destroyed.
A slurry of D.E. compound can be made up to use in a sprayer for precise coverage, or when larger areas, like a tree trunk must be treated. In a 5-gallon sprayer, add 1 teaspoon of flax or insecticidal soap and fill with water. Flax soap can be purchased from a paint supply store.
Using Diatomaceous Earth Safely
When mixing or applying D.E., be aware of the proximity of air conditioning units or other appliances or equipment that could be harmed if the fine dust gets into the motor.
When using diatomaceous earth, wear a dust mask to protect mucous membranes in the mouth and nose from irritation. Don't use utensils that will later be used for cooking or drinking. Harvest fruits and vegetables before dusting, and wash hands after handling.
D.E. will also kill beneficial insects, so only use in areas of infestation. The powder will wash away with a heavy rain, so another treatment may be needed.
Sources:
Maryland Department of Environmental Protection: Diatomaceous Earth & Dessicants
Ohio State University: Insect and Mite Management Alternatives
Ball, Liz, Ball, Jeff, Flower Garden Problem Solver. Pennsylvania: Rodale Press, 1990
Patrice Campbell - Patrice Campbell is a freelance writer working from the Denver, CO area. As an experienced news reporter and lifestyle writer, Patrice ...
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