Vulnerable Plants

• All trees and plants can suffer the effects of freezing temperatures, but young or actively growing trees of all species, as well as those which are dehydrated, diseased or otherwise stressed, are more vulnerable to frost damage. Frost-caused cankers and cracks can develop quickly on the sites of existing lesions and breaks in the outer bark of damaged trees.
  
  

Spring Freezes

• Late spring freezes, occurring suddenly after a period of warm weather, can damage new, actively growing tissue such as leaves and buds. Symptoms of late spring freeze include brown or black, curled or shriveled leaves and withered buds. Some pockets of leaf tissue can be injured by frost, resulting in holes or tatters resembling insect damage. Early fall frosts also cause this type of damage.
  
  

Winter Frost Symptoms

• Winter freeze symptoms,caused by extended cold periods, include frost lesions on outer bark, such as cankers and cracks. In conifers, necrotized bark can slough off, exposing vulnerable inner layers. Raised outer layers called frost ribs develop around older cankers, and repeated exposure to freezing temperatures can create deep cracks. Needles and other remaining foliage can become blackened and withered.
  
  

Survival of Affected Trees

• Mature trees can survive even severe frost damage, although very young ones with thin, developing trunks may not. Frost damage, particularly from sudden late spring frosts, can kill emerging buds and fruits, with losses of entire fruit crops. Injury to actively growing tissues and new buds can stress trees and limit fruit and flower production through the next growing cycle. Growers advise taking preventive measures such as covering vulnerable trees when freezing temperatures are expected, and keeping trees hydrated to improve chances of survival.