Control and Prevention

How to Get Rid of Cabbage Worms

• Manually remove (handpick) the eggs if possible.
• Yellow sticky traps will catch the adult butterflies, but may also catch beneficial insects.
• Spraying with BTK (Bacillus thuringiensis var. kurstaki) every 1 to 2 weeks will also help control cabbage family pests. Sevin also is effective. And, the few pests that remain on the vegetables can be washed out after harvest using water and a small amount of detergent or other surfactant.
• It is said that if you dampen cabbage leaves and sprinkle them with cornmeal, the caterpillars will eat the meal, swell, and die.
• Check with your local Cooperative Extension for your area’s regulations on chemical control.
• Old folk advice from The 1963 Old Farmer’s Almanac states: Years ago, people sprinkled rye flour over cabbage plants in the early morning. The flour dehydrated the cabbage worms. Give it a try!

Prevent Cabbage Worms

• Cover your plants with row covers to deter the adult butterflies from laying eggs on the cabbages.
• Trichogramma wasps (very tiny; they do not sting humans) parasitize the eggs of the imported cabbage worm; these beneficial insects are available by mailorder, although you’ll need to time their release appropriately—the mailorder company would be able to help you. Read more about beneficial insects.
• Companion planting is a useful deterrent for many pests. Cabbage worms are repelled by thyme, so it would be a good idea to plant thyme near your susceptible plants. Cabbage worms are attracted to mustard plants, so planting mustard near more valuable plants can be a good trap for cabbage worms. Once they take over the mustard, you can destroy the plant.
• Try planting red leafed varieties of cabbage. The cabbage worms won’t be able to camouflage, so they are less likely to choose these plants.