Is Diatomaceous Earth Good for Plants?

Natural Substance

• Diatomaceous earth or diatomite is a chalky powder made from ground deposits of diatoms. Diatoms are unicellular plant organisms fossilized 30 million years ago into the sea bed. The sediment is comprised of many nutrients including magnesium, calcium, copper, boron, sodium, iron, titanium and manganese. These substances add life to plants by feeding the microorganisms living in the soil.

Soil Additive and Water Conservation Aid

• Adding diatomaceous earth to soil increases nutrients to plants through the addition of organic matter to the soil. Mix generously into hard-pan clay soils to break up tiny clay particles, increase aeration and water flow. Diatomaceous earth boosts irrigation efficiency by absorbing three times its weight in water. Use in addition to mulch to decrease water usage.

Organic Pesticide

• Diatomite is a natural lethal powder for garden pests who digest or contact it. The razor-sharp dust damages the exoskeleton and causes internal lacerations once consumed. Sprinkle around seedlings or spray watered-down powder onto leaves to prevent egg laying. It is successful at protecting seedlings from pill bugs and slugs. Use to deter flea beetles, sawfly, earwigs, coddling moths, ticks, bedbugs, silverfish, twig borers, ants, mites, cockroaches, slugs, snails, aphids, gnats, fleas and silverfish.

  Diatomaceous earth does not kill earthworms, soil microorganisms and other warm-blooded animals due to structural differences. Earthworms add health to soil by digesting nutrients and making them accessible to plants.

Safe and Correct Application

• Be sure that natural, food-grade diatomaceous earth is used. Do not confuse with pool-grade diatomaceous earth, which is crystallized and used in filtration devices; it should never be used in the garden or household.

  Apply the proper version with a dust mask. The powder may be dangerous for human ingestion in large amounts. Sprinkle 1 tbsp. of the powder directly around each newly planted seedling. Diatomaceous earth may be applied using a pest pistol or compression sprayer. Mix one part diatomaceous earth to three parts water, if using a sprayer. A slurry of diatomaceous earth and water can also be applied directly to tree trunks to discourage climbing pests.