How Temperature Fluctuations Cause Sunscald

The term “sunscald” may conjure images of cracked dirt and blazing sunlight, but experienced landscapers know that sunscald primarily affects trees during the winter. Sunscald is a tree injury caused by rapid temperature fluctuations. Warm winter days or cold afternoons with strong sunlight can trick trees into prematurely exiting dormancy. The tender tree, ready for spring growth, goes into shock when the temperatures drop again. Plants suffering sunscald may develop cracks, dead spots, or disease. Young trees are more susceptible to sunscald than established plants, but trees like maple and hawthorn have dark bark and absorb more sunlight, increasing their risk of cold weather sunscald. Sugar maples in particular have thin bark, making them a likely candidate for sunscald damage.

Preventing Sunscald

frosted leavesWinter tree care reduces the likelihood of sunscald in your deciduous and ornamental trees. Historically gardeners would protect their trees from temperature change by whitewashing the bark. Painting your tree not only protects the bark from direct sunlight, but also gives your orchard a clean, cohesive aesthetic. Although this method is effective, nurseries have developed simpler methods of ensuring tree health. Wrapping the trunk in plastic reflects sunlight and insulates your dormant plant, regulating the temperature of your tree’s tissue. White tree wrap is available at most gardening and home improvement stores. Mulching the roots of your plant also insulates your tree, contributing to its health during the winter months.

Choosing Your Trees

A major factor in avoiding winter tree injuries like sunscald is choosing the correct tree for your location. Explore hardiness zones, soil types, and hydration requirements before purchasing your trees. Call your professional Alabama horticulturalists at 3am Growers for more information on planting and developing trees.