Courtesy of the University of Illinois Extension
Exploding trees made quite a few headlines this past week when winter temperatures dropped across much of the country. While the claim of trees exploding certainly grabs attention, it is a little exaggerated. So, what was behind the frenzy? Is there some truth to the concern?
The reality behind these dramatic headlines is a process known as frost cracking. While a sharp crack may be heard on in the woods on a silent night, the tree explosion is not the catastrophic fire filled explosions of an action movie… although the plot line of what leads up to the big event is captivating. Frost Cracking
During winter, trees face a variety of environmental stresses. Frost cracking, also called frost splitting or sunscald- related cracking, is a dramatic ailment that can lead to long-term health challenges for a tree.
Frost cracks appear as vertical splits in the trunk of a tree and are the result of plant tissue expansion and contraction following winter temperature fluctuations. During winter days, sunlight warms the bark and outer layers of tree trunks, especially on the southern side of a tree. When night falls, temperatures can drop quickly, causing the warmed tissue to cool and contract. If the contraction of outer layers happens faster than inner layers, resistance can cause stress that may exceed the strength of the wood fibers, resulting in a split.
