What is wrong with my tomato plant?

Asked July 23, 2014, 10:53 AM EDT

My tomato plant, which is growing in a three-foot-square planter, seems unhealthy. Its leaves are curling inward; it is quite large but has virtually no fruit; and blossoms are falling off the stems. The problem does not appear to be early blight. What might be wrong with the plant? I'm afraid that I might have to euthanize it.

Monroe County Michigan

3 Responses

Tomato diseases result in marking of the leaves and/or fruit.

Rolled leaves are a physiological problem (not a problem caused by insects or disease). The edges of the leaves roll upward and inward. They may roll so completely that the sides touch each other. This problem is the result of irregular water supply to the plant. Symptoms are intensified by pruning. Correct the water problem, and the plant should return to normal.

Irregular water supply to a tomato plant will not cause the flowers to fall off. If flowers are not pollinated, they fall off. Tomatoes are wind pollinated, so if the plant is in a sheltered area, there may not be enough wind to cause the pollen to float around.

If any twisting, curling, or elongated stem growth is associated with the leaf curling, the problem could be damage from 2,4-D, a broadleaf herbicide that is put on lawns. In warm weather, the material can turn into a gas soon after application and make contact with susceptible plants, such as tomatoes. If the dose is light enough, an affected plant eventually grows beyond the problem.

I tried heavy watering, but the plant didn't respond. It is located in an open area where wind can reach it. I clipped a few branches, but I have done no significant pruning. Do you have any other ideas about what might be wrong with the plant?

If the only problem is curled leaves, the plant should begin making normal leaves in a week or two.

No disease or insect problem causes leaf curl. Leaf curl is a physiological problem. You do not need to water the plant heavily. Instead, you need to water it regularly. Water all the way around the plant, and water the plant well enough that water comes out the drain holes in the planter.

Killing the plant solves nothing. What do you have to lose at this point by waiting to see whether the plant will improve?