01/26/2026
Myth-busting Monday...Let's learn a bit more about exploding trees🌳.
Can trees explode in subzero weather? Buckle up, it’s time for University of Illinois Extension Forestry to bust some myths about “exploding trees.”
Native trees are used to and can survive the shifting temperatures in their home ranges, but bitterly cold conditions can be a challenge. What happens if the temperature drops really cold, really fast? The outside of the tree contracts faster than the inside, creating an imbalance of pressure.
BANG! That pressure release suddenly splits the tree vertically along its trunk, a phenomenon known as frost cracking. Sometimes, that cracking comes with a loud popping noise that can sound like gunfire, but it’s not an explosion.
What kinds of trees are affected? Many thin-barked trees in the home landscape are susceptible to this kind of winter damage, including fruit trees, maples, lindens, sycamores, willows, and young trees. Frost cracking often happens when the tree is warmed by strong direct sunlight during the day and then refreezes quickly at nightfall.
How do the cracks affect the tree’s health? Since it is a vertical split, the trees are generally not significantly affected. But the length, width, and depth of the cracks can vary.
You may not notice a frost-cracking wound on landscape trees until spring or summer. Cracks can close up and then reopen in future winters, or the tree may grow over the crack, forming a callus. Over time, branch dieback can happen, and the tree’s health may start to decline, putting it at risk of damage from other environmental stressors like insects and decay.
Planting susceptible trees where they will be protected from the late afternoon sun can help prevent frost cracking. Using tree wrap can prevent temperature fluctuations. Apply wraps in November and remove them in April. Leaving wraps on all year can cause damage or restrict growth.
Questions about trees or landscape care? Connect with staff at your local Illinois Extension office at https://go.illinois.edu/ExtensionOffices. Learn more about Illinois forests at https://extension.illinois.edu/forestry.
Have any frost crack photos of your trees? Comment with a picture!