Drescription

Tomato plants are the most commonly grown vegetable in the garden because they thrive in summer temperatures and produce delicious fresh produce.1

Novice and experienced gardeners carefully plant and tend the tomato plants, only to discover the plants wilting and dying one day. The cause can be something as simple as a lack of water or more complex, like fungal wilt diseases, tomato wilt viruses, walnut toxicity, or boring insects.

When you discover a wilting tomato plant, it's important to act quickly and decisively to protect your other tomato plants. Follow our guide on the causes of wilting tomatoes and suggested fixes.

Lack of Water

Healthy tomato plants planted in garden soil require approximately one inch of water per week, and container-grown plants require approximately one gallon of water daily. A lack of water will cause the tomato plants to wilt, but if that is the only cause, they will revive rapidly after watering.

Solution: Regularly apply water directly to the soil with a garden or soaker hose. To maintain a consistent level of moisture stick your finger into the soil at the base of the plant. If the soil is moist at a depth of two inches, don’t water but check the soil again the next day.

If the soil is dry to the touch at a depth of two inches, slowly apply water to the plants so the water seeps into the soil. If you must use an overhead sprinkler, water in the morning so the foliage dries quickly to help prevent disease.

Fungal Wilt Diseases

Striking without warning, verticillium and fusarium wilt are two common causes of a seemingly healthy tomato plant wilting and dying within a few days. Both diseases are caused by fungal spores in the garden soil. The spores enter the plant through the root system and block the movement of water and nutrients. This causes the plant to wilt, turn yellow, and die.

Other fungal diseases, early tomato blight and southern blight may not kill the plants but will greatly inhibit their fruit production.

Solution: Unfortunately there is no treatment for fungal wilt diseases. The infected tomato plants should be removed and discarded. Do not place the diseased plants in your compost pile to help prevent the spread of the fungi.

To help ensure healthy plants in the garden, rotate crops and do not plant tomatoes, peppers, eggplants, or potato plants in the same location every year. Since the fungi can live for several years, consider container-grown tomatoes for several years. You can also select tomato varieties that are resistant to fungal wilts. Look for plants labeled with 'VF' on the plant tag.

Tomato Wilt Viruses

Dozens of tomato viruses can cause tomato plants to wilt and die.2

Two of the most common are Tomato Spotted Wilt Virus (TSWV) and Tomato Mosaic Virus (ToMV), which cause stunted growth, wilting, and unattractive fruit. The source of the virus can be other plants, seeds, or insects. The virus can be spread from one infected plant to others through your hands, gloves, or tools.

Solution: There is no treatment for these viruses, and the plants should be removed and discarded to help prevent the spread of the virus. Look for virus-resistant varieties, rotate crops regularly, and wash your hands and garden tools after handling infected plants to help prevent the spread.

Black Walnut Toxicity

Black walnut trees and tomatoes do not belong together. All parts of the tree exude juglone, a toxin that causes stunted growth, wilting foliage, and death for tomato plants. Since the greatest concentration of juglone exists nearest the tree, plant tomatoes at least 20 to 25 feet away from the tree's dripline.

Solution: Unfortunately, juglone cannot be eliminated from the soil and once tomatoes are affected, there is no treatment to save them. Removing the tree will not solve the problem because juglone can be found in the root system after the tree is cut down. If your gardening space is limited, consider container-grown tomatoes.

Boring Insects

The stalk borer is a purple and cream-striped caterpillar that can attack tomato plants and cause wilting and death of the plant. The caterpillar bores into the stem through a tiny hole and tunnels inside the plant destroying tissue.

Solution: Once the borer has done its damage, the tomato plant should be removed and destroyed. There are no insecticides that will control the larva of this inconspicuous grayish-brown moth. To help prevent borers, keep weedy areas around the garden mowed well.

How to Help Prevent Tomato Wilting

Maintain a steady watering routine. Monitor weather conditions and provide one to two inches of water per week to the roots of the tomato plant. Do not allow the soil to become overly dry or overwater so the roots are left soggy.

Provide adequate spacing between plants. Plant so that there is space between each tomato plant for air to flow freely to help prevent air-borne diseases.

Practice crop rotation. Do not plant tomatoes in the same locations year after year. Rotate crops to allow soil-borne diseases to die.

Maintain an orderly garden. Remove weeds that can attract harmful insects and spread diseases. Mulch to help maintain soil moisture. Cage or stake tomato plants to keep the fruit off the ground to limit disease spread.

Buy disease-resistant seeds or transplants. Read seed packets, catalogs, and plant tags carefully to select disease-resistant tomato varieties. Cornell University maintains an excellent list to help you with plant selection.