Tomato Vines & Wilt

Water

• Tomato plants wilt when they don’t receive enough water. Provide your plants with 1 inch of water every week during the early part of summer and with 2 inches from July on. Water thoroughly, soaking the soil to a depth of 12 to 18 inches. Avoid overhead watering, if possible, because wet leaves encourage fungal diseases.

Nematodes

• Nematodes are microscopic worms that live in the soil and attack the roots of tomatoes, causing plants to yellow and, in severe cases, wilt. Examine the roots for the presence of galls. Plant resistant varieties and plow or spade the soil after harvest to control nematodes. Soil fumigants or nematicides are also effective.

Borers

• Stalk borers are purple and cream striped caterpillars with purple bands around their bodies. They attack a wide range of plants, including tomatoes, by tunneling through the stalk as they feed. Plants wilt and usually wind up dying. Insecticides don’t work against borers. Clear out weeds from around the garden and pull and destroy any dead tomato plants to help control them.

Fungal Wilts

• Fusarium wilt and verticillium wilt are fungal infections with very similar symptoms that include yellowing leaves and daytime wilt. At night, the plant returns to normal but, as the disease progresses, it’s unable to recover and remains wilted. In addition, fungal wilts cause tomatoes to become stunted and the water conducting tissues inside the stem turn brown. These diseases require a laboratory diagnosis to determine which is infecting your plants. Control fungal wilts by planting resistant varieties. Remove and destroy infected plants and plant parts. Rotate crops every four years. Fungicides are ineffective against these diseases.

Bacterial Wilt

• Bacterial wilt causes leaves growing at the tips of stems to wilt first. A couple of days later, the entire plant wilts suddenly. In addition, the roots and water conducting tissues in the lower stem turn brown, and a yellowish or gray bacterial ooze leaks from stems that are cut open. Chemicals are ineffective against this wilt. Control it by using disease-free transplants, resistant varieties and by pasteurizing or fumigating the soil.

Stem Rot

• A fungus is responsible for stem rot. It causes scattered plants to suddenly and permanently wilt without turning yellow first. White fungal filaments grow on the stem near the soil line. Stem rot is worse when the soil is wet and the temperatures are high. Soil fungicides offer limited protection.

Tomato Spotted Wilt Virus

• Tomato spotted wilt virus is spread by thrips, and no tomato variety is resistant to it. You must remove infected plants. Symptoms include the appearance of orange flecks on young leaves. In addition, plants are stunted, wilted and brown and green rings appear on the fruit. Although the disease can’t be eliminated, controlling weed hosts like chickweed, mallow and nettle may reduce the problem.