How to Identify Tree Freeze and Thaw Damage

Trees thawing after a freeze.During the winter months, trees are vulnerable to freeze and thaw damage. Colder nights followed by warmer days cause continuous shrinking and expanding of the trees, as their barks shrink when it is cold and expand as it is warm outside.

Blair County winters are particularly damaging to trees.

Some of the most common problems that occur because of freeze and thaw cycles are bark and roots cracking.  To learn how to identify potential problems early continue reading.

Freeze and Thaw Cycles

You may have already noticed damage on your tree and not realized that it was from the free thaw cycle. Here’s how the cycle works, so that you can understand the cause of your tree damage. Trees function according to temperature outside. If it is cold outside, tree cells are inactive, and if it is warm the cells are active again. During the winter a sun-facing trunk on a clear day can be warmed up to the point when the cells are active. Usually it is the southwest side of the bark that warms the fastest. Much of the time, however, tree cells are inactive during the cold winter days and nights.

When there are temperature swings or particularly sunny days, tree cells are put under a lot of stress switching between active and inactive states sometimes causing them to die off. When tree cells dies as part of the free and thaw cycle, vertical cracking may occur and these cracks can be “attacked” by decay fungi and various insects.

Also, moisture on the surface of the bark thaws when it is warmer. This can be problematic because when the sun goes down, the moisture that is still in and around the bark will refreeze. This phenomenon causes cracks and splits damaging the tree, but not in areas where large groups of trees protect each other. If you are not sure where those cracks in your tree came from or what to do about it, call a professional.

When the upper layers of soil expand during the day as sunlight begins to warm up the ground and thaws the surface, and then shrinks again during the night when it gets colder, frost heaving occurs. This cycle of shrinking and expanding of the ground may result in cracks in the soil. Even worse, it can result in roots breaking, pushing shrubs out of the soil, and causing pot holes.

Dark colored bark and large trunks also contribute to freeze and thaw damages. Dark colors absorb sun rays instead of reflecting them thus these trees with dark bark refreeze more quickly when the temperature drops. Larger tree trunks need more time to warm up than trees with narrower trunks. Their surface is smaller and therefore they suffer less from freeze and thaw cycles.


Pay close attention to your trees during the winter months especially if they are dark colored and with large trunks. Inspect them closely to see if there are cracks or fungi as well. When you notice a tree has damage from the free thaw cycle, give Reliable Tree Service at (814) 693-TREE or visit our contact page to save your tree from further damage.

My Reliable Tree Service
305 15th St. Suite 6 DuncanvsillePA16635 USA 
 • 814-693-TREE

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>