A widespread and destructive disease, verticillium wilt is caused by a fungus that invades and plugs water-conducting tissues in roots and stems. A common symptom is wilting on one side of the plant. Leaves turn yellow, then brown; then they die. Many plants are afflicted. Highly susceptible crops, such as tomatoes, potatoes, cotton, strawberries, and various melons, frequently leave the soil infested--and the fungus can survive in the soil for years in the absence of susceptible targets. Even crop rotation will not eliminate it.

Resistant plants are the best defense against verticillium wilt. A number of resistant trees, shrubs, flowers, bulbs, and vegetables are available; contact your Cooperative Extension Office for a list of those sold in your area. Plants resistant to verticillium wilt are often also resistant to the disease fusarium wilt.

If the problem is so severe that you must resort to chemical control, call in a professional to fumigate the soil.