Chicago Botanic Garden

YOUR GARDEN — Plant Information

Pests, Problems, and Diseases

Frost Cracks

 

Susceptible Plants
Deciduous trees, especially young trees with thin bark planted in sunny, exposed sites.

Description & Symptoms
Vertical cracks appear in the winter in the bark of young trees, particularly on the side of the trunk oriented to the south or southwest. This is a mechanical process caused by the expansion and contraction of bark in response to warm daytime temperatures and cold nighttime temperatures.

Timing & Life Cycle
Frost cracks are a winter problem that is especially severe if warm afternoon sun is followed by a rapid drop in temperature at sundown. Reflected light from snow cover can exacerbate the problem.

Damage
Frost cracks cause wounds in the bark of a tree that can lead to infections and decay.

Treatment & Solutions
Healthy trees will seal off a wounded area and form callus tissue around it. Siting trees properly and providing water during dry periods, particularly in the fall, will help trees resist cracking during winter. Stressed trees are more susceptible to frost cracks. Plant choice is also a factor. Woodland trees that prefer shade are more likely to crack if planted in a sunny location. Recent studies indicate that wrapping tree trunks is not an effective technique for avoiding frost cracks.

 

For more information about frost cracks, call the Plant Information hotline at (847) 835-0972.