Plant woody plants where they can adapt to climate and soil conditions. Woody plants have to harden off properly to prevent fall frost damage. Temperature extremes and rapid fluctuations can harm most plants. Because many shade trees and woody ornamentals planted in Colorado are not native, they often are injured by temperature extremes, or temperature extremes coupled with moisture stress. Sunscald Sunscald occurs during cold, bright days in midwinter.
Direct sun rays heat south-facing branches and southwest sides of tree trunks.
This raises bark temperatures above freezing and causes some cells to become active. After sunset or with changing weather conditions, the bark experiences a sudden temperature drop, killing the activated tissue. Bark in the affected area may initially turn red, orange, yellow or some other hue not consistent with normal bark color. The bark then may crack, become mushy, or slough off in patches revealing dead tissue underneath. These symptoms usually occur on the tree's southwest side.