Diatomaceous Earth

Credit: Andrew Rollinger

The talcum-like powder can be sprinkled around infected plants, mixed with water and sprayed on, or made into a paste and painted on. It consists mostly of silicon, with small amounts of iron, sodium and magnesium, trace elements and minerals. When working with it, always wear a dust mask, as it is a very fine powder and you do not want to inhale it. Be sure to keep pets away while using as they should not inhale it either.

The product’s razor-sharp edges affect pests either internally or externally, resulting in death. Since pests are not able to develop a resistance to it, diatomaceous earth is a long-term, non-chemical pesticide.

You can find diatomaceous earth at garden centres, in seed catalogues or at feed stores.

Diatomaceous Stem Paste
250 mL (1 cup) diatomaceous earth
375 mL (11⁄2 cups) water

Mix diatomaceous earth and water. Using a paintbrush, apply the thick paste to the trunk of any tree infected by insects. Apply it at least 45 cm (11⁄2 ft.) up the trunk. Works well to keep ants and pill bugs at bay.