DAMAGE/SYMPTOMS Frost cracks are vertical splits that occur in tree trunks and bark after severe, rapid temperature changes in the winter. Damage usually occurs on the south or southwest side of vulnerable trees because those sides experience the greatest fluctuation in temperature. Frost cracks can reopen and enlarge in subsequent winters and may extend to the center of the tree.

OCCURRENCE When temperatures are below 15 degrees, frost cracks may form due to the shrinking and expansion of wood in relation to water movement and ice formation. Young trees and smooth barked trees are more likely to sustain damage.

SUSCEPTIBILITY/TOLERANCE Maple, birch, poplar, apples, and ash are susceptible to frost cracks.

MANAGEMENT To avoid frost cracks in young trees, a trunk guard can be installed. These guards are usually white and reflect sunlight from vulnerable surfaces. They should be installed in the fall and removed in the spring. Leaving them on year-round can promote fungal and insect issues. If damage occurs, monitor trees for the development of decay. Reduce stress and encourage tree vigor through proper watering and pruning. Do not treat frost cracks with “wound paint”, as these products do not reduce the chance of decay.

 

A Green ash often show frost crack damage. B Frost cracks generally appear on the south and southwest sides of trees.

 

A large tree trunk with a calloused spiral wound from the ground up to seven feet.

A photo of a tree trunk with a wound on one side of the trunk. A large building and sidewalks are near it.