Leaf Roll Leaf roll of tomatoes is caused by unfavorable environmental factors. High temperatures, prolonged periods of wet soil conditions, and drought may promote symptom development. Leaf roll is characterized by the upward curling of leaflets on older leaves. Rolled leaves may feel firm and leathery. Symptoms may affect up to 75 percent of the foliage, although plant growth and fruit production are not altered significantly.
Symptoms are most common when plants have a heavy fruit set.
Controlling leaf roll is not a major concern since damage is minimal. Setting plants on well-drained soil and irrigating during periods of drought will help prevent the appearance of leaf roll. Leaf roll has been associated with varieties having a specific gene that favors this condition. Use pesticides only according the directions on the label. Follow all directions, precautions, and restrictions that are listed.