Natural Ways to Kill Tomato Worms

Hand-Picking, the Simplest Technique

• Gardening experts agree that picking the worms off by hand and dropping them into a bucket of water is the easiest and greenest method of disposal. The main drawback may be difficulty in spotting them, as their colors mimic those of the plants'. Colorado State University suggests scheduling the chore close to dusk or dawn, as the worms are usually actively chewing at the shadiest times of the day. They should stand-out from the background then and be easier to locate. Do not kill any with tiny white cocoons on their backs, warns the Gaston (NC) Gazette, as they have been preyed upon by a tiny wasp. The worms will die anyway, and at their death more parasites will be produced to kill other hornworms.

Help from Predators

• The small braconid wasp can be purchased, as can ladybugs and green lacewings. The two latter mentioned, will kill hornworms in the egg stage and early larval stage, according to the University of Minnesota. Another natural enemy of tomato hornworms, the common wasp is capable of consuming a large population of the garden pests. Some gardeners build small wasp houses in trees, or on poles near the vegetation to attract colonies of wasps, reports the Gaston Gazette. Protecting these beneficial insects is another reason not to use chemicals to eradicate the hornworms.

Bacterial Sprays and Home Remedies

• Instead of treating the tomato plants with commercial insecticides, spray your garden with Bacillus thuringiensis (Dipel or Thuricide). This releases a bacteria that, when eaten by the worms, will kill them within a few days, according to an article in the Daily Puppy. If you do not want to purchase this product, spraying the plants with vegetable oil or liquid soap should make the plants unappetizing to the hornworms. Hot pepper sauce may also be added.

Preventing Hornworms

• The best anti-hornworm measures can be taken before planting. When the soil is roto-tilled after harvesting, up to 90 percent of the worm larvae -- burrowed in the soil waiting to emerge the next year -- will be killed, claims the University of Minnesota. Companion planting may offer some protection from hornworms, as well as other garden pests. Traditionally, marigolds or dill are planted with tomatoes for this purpose.