Sun scald

Sunscald on trees is visible in the form of damaged or discolored bark on the south or southwest side of the trunk and lower branches. The sun heats the bark during the day in winter or early spring, which activates the cells, but then rapid cooling at night damages and kills the bark tissue. Such sunscald often shows as sunken, cracked, or peeling bark and can expose inner wood, allowing pests and diseases to become established. Sunscald is primarily caused by temperature fluctuations and changes in sunshine hours, and can be particularly damaging to young or thin-barked trees with no natural protection. To treat and prevent sunscald, the major emphasis should be placed on protecting susceptible trees; either wrap the trunk in tree guards or protective wraps in the winter months; mulch the tree to help maintain consistent soil moisture; and make sure the tree is healthy through adequate watering and fertilization. Removing damaged bark is also very helpful; however, it is also important to look out for secondary infections and pests that will take advantage of the damaged areas. Any action that promotes the tree’s recovery will have a positive effect on further injury from sunscald.