Leaf Rolling (Cupping) of Fruit Trees, Ornamentals and Vegetables

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

Leaf roll of tomato ('Early Girl' variety, I think) during summer heat but the leaves look fine otherwise

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.

Leaf roll of mockorange (Raphiolepis) during the heat of summer (in northern climates the common name of mockorange is a different plant, Philadelphus). Had me confused for awhile.

If your plant is showing lots of leaf roll during the summer 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, a balance between watering too often and not watering often enough. 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 and leaf roll due to irrigation and conserve moisture. Sometimes its just damn hot!