Natural Repellent for Cabbage Worms

If left unchecked, cabbage worms may devastate cole crops---a family of vegetables that includes cabbage, broccoli and kale---by devouring their leaves. Steps may be taken, however, to control cabbage worms without resorting to harmful insecticides.

Cabbage worms are caterpillars with black stripes around their backs and yellow stripes running along their sides. They feed on growing tips and young leaves of cabbage and its relatives, including broccoli, cauliflower and Brussels sprout. Adults are yellowish brown moths, which lay masses of flat yellow eggs in spring and summer.

Caterpillars may be removed by hand. Eggs should be crushed and the caterpillars should be dropped into soapy water to kill them.

Row covers may be used at planting time and left in place until harvest. They create a mini-greenhouse over the plants, discouraging moths and preventing them from laying eggs.

Garlic or hot pepper sprays discourage moths from laying eggs on your plants. Neem spray, an extract from neem tree seeds, works against caterpillars.

Apply Bt (Bacillus thuringiensis) or spinosad when the caterpillars are young. These insecticides contain organisms that eliminate caterpillars, but they don't harm any other form of wildlife. It takes the caterpillars a while to die, so don't be concerned if you continue to see them on your plants for a couple of days.

The caterpillars are more visible and therefore easier to control if your cabbage is a red or purple variety. Crinkly leaved varieties of cabbage give caterpillars lots of places to hide.

Cabbage worms often come to the garden on transplants, which therefore should be inspected closely prior to purchase.