By Barbara Fahs, Garden Guides Contributor

About Root Maggots

The cabbage root maggot is a common pest that attacks the roots of many vegetable crops. In its adult stage, this maggot is a gray fly, similar in appearance to the housefly. It's less than 1/3 inch long and is white. Other types of root maggots include the onion maggot. Both maggots are common in the northern United States.

Prevention and Control

A floating row cover over your cabbage family crops can help prevent a root maggot infestation. Because the adult fly cannot get in to lay its eggs near your plants, they will be safe from the larval stage, the root maggot itself. If you place row cover in the spring and summer, you should be able to foil the root maggot, as the adult fly is not active in winter months. If you discover any maggots, pull affected plants and destroy them.

Affected Plants

The cabbage family is especially susceptible to root maggots; broccoli, Brussels sprouts, cabbage, cauliflower and kale are common victims of this pest.

Damage

The root maggot hatches at the base of plants and then tunnels into the plant, where it feeds and eventually kills the host plant.

Predator Insects

Tiny nematodes can help control root maggots.

Natural Insecticides

Tests are being conducted with a natural soil fungus as a control for root maggots. It won't hurt seedlings or good insects like ladybugs. Watch for news about its development in the near future.

Other Methods of Control

Keeping the garden clean around your cabbage family plants can help deter root maggots. Healthy, robust plants are less likely to be attacked.