Natural Pesticide for Tomato Plants


Tomatoes are one of the easiest vegetables to grow, even if you don't have a green thumb. From a large garden patch to a pot on the city-dweller's patio, tomatoes are one of the most versatile veggies around. Endless varieties offer options in size, flavor and growth rate. Using natural ways to eliminate common tomato pests is safer, especially if you have small children and pets.

Naural Predators

Hornworms are one of the most common and destructive tomato pests, destroying leaves. Ladybugs and lacewings are natural predators of the tomato hornworm and will eat the eggs. Although most people prefer not to have wasps around, the braconid wasp also eats hornworm eggs. If you see a hornworm with a white pouch on its back, don't kill it. The pouches contain wasp eggs, which will eat the worms.

Bacillus thuringiensis (Bt)

Bacillus thuringiensis (Bt) is a naturally occurring bacterium found in soil. It is the only microbial insecticide currently in widespread use. It kills many pests and was first discovered to be insecticidal in 1911. One of its biggest advantages is that it is nontoxic to people, pets and wildlife. This makes it particularly suited for use on food crops. Instead of attacking the nervous system, Bt works by producing proteins, which paralyze the digestive system of the insect,starving it to death. It takes a few days to work, and many people mistakenly think that it is not working when they don't see instant results. It works well on flea beetles and hornworms, which destroy the tomato's leaves.

Insecticidal Soap

Insecticidal soap, such as Safer Soap, controls soft-bodied insects by smothering and dehydrating them. It can be used on many vegetables, fruits, trees, lawns, shrubs and flowers. It kills aphids, thrips and whitefly on tomatoes. One of its advantages is that it can be applied to tomatoes up to the day of harvest.

Diatomaceous Earth

Diatomaceous earth (DE) is a naturally-occurring mineral compound composed of microscopic skeletal remains of unicellular algae-like plants called diatoms. DE is mined and ground into a fine powder, similar to talcum powder. Its shape gives it microscopic razor-sharp edges which cut through an insect's protective covering. If the insect ingests DE it shreds their insides. It destroys aphids, thrips and flea beetles on tomatoes. It's important to only use DE specified for plants. DE is also used in swimming pools; however this form of DE should never be used on plants. Always use a mask when applying to avoid inhaling dust.


A combination of methods may work the best, depending on your particular pest problem. Look for insect-resistant varieties of tomatoes, if available in your area. Always rinse tomatoes thoroughly before eating. Act as soon as you notice a problem; prolonged waiting means more crop damage and a lesser chance of controlling infestation. When purchasing tomato plants, look for healthy, vigorous young plants free of damaged leaves and roots.

Keywords: natural tomato pesticides, organic tomato pesticides, tomato pesticides

About this Author

Roma Lightsey has a B.A. in communications, as well as a B.S.N. Currently, she works as an R.N. in a large city hospital and is pursuing her M.S.N. She has written for "Grit" magazine and a health column for a local newspaper. Lightsey is a member of several RWA (Romance Writers of America) chapters.