Cupping or Rolling of Plant Leaves During the Heat

Q. Why are the leaves of my fruit trees cupping or rolling?

Leaf roll or cupping on pepper plant even though its mulched

A. Fruit tree leaves of apples, pears, pistachios, tomatoes, and other plants in full sun all day long will sometimes cause the leaves of some varieties to cup or role. Excessive irrigation and fertilizer, high temperatures, the variety of the tree or plant, overly dry soils, root damage and planting shock are some of the environmental factors that can cause physiological leaf roll in fruit trees. Over time all the leaves on the plant may be affected.

Tomato leaf (probably 'Early Girl' cupping or rolling

If your plant is showing lots of leaf roll first blame the high temperatures of summer. Leaf rolling won’t hurt the leaves as long as they remain soft and pliable. Next, be careful of irrigations. Irrigations should keep the soil consistently moist for most garden plants and not allow the soil to dry out rapidly. Apply a surface mulch to slow water loss from the soil and reduce plant stress. Woodchips, straw, shredded newspaper applied a few inches deep will slow water loss from the soil, reduce fruit cracking due to irrigation and conserve moisture.

Leaf roll of mockorange landscape shrub (Raphiolepis spp.)