It is a common sight to see red maples along a walking path or sidewalk in an urban setting with one side of the bark damaged and cracked.

It is a common sight to see red maples along a walking path or sidewalk in an urban setting with one side of the bark damaged and cracked.
When I was going to school at Missouri State University in Springfield, Mo., there was one maple in particular which I passed every morning that seemed to be eaten away on one side with only a thin section of the trunk and bark remaining.
The cause of this ailment was not a living disease, but actually the environment.
The winter is a harsh time of year and can put a great deal of stress on sapling trees with thin bark.
This week's article is on protecting trees from the harsh effects of fluctuating winter temperatures.
Has the bark of a young red maple, fruit tree or other thin bark tree in your yard appeared to crack and split on the southwest side during the winter leaving it gashed and callused?
Just like the tree I passed in Springfield, this damage to the southwestern side of thin barked trees is called sunscald injury and is caused by warm winter sunlight and temperature fluctuations.
The problem is that during the late winter in the Missouri Ozarks we tend to have drastic temperature swings all within a few hours of time.
It can be sunny and 63 degrees one afternoon, and 28 degrees the next with temperatures dropping to 16 degrees at night.
These changes in temperature place stress on the cells under the bark of the trees, especially thin barked trees like red maple.
This stress is often is too much for even cold, hardy native tree species to endure without damage.
According to Colorado State Extension, sunscald injury is most prevalent on the southwestern side of trees because that is the side of the tree which receives the most sunlight and when it warms that side of the tree is tricked into breaking dormancy, only to be devastated when temperatures plummets and its bark cools to actually normal frigid temperatures.
Stressed trees whose cells have been damaged by the warm to cold temperature changes can appear as if their bark has been gashed and cut as other necrotic callused tissue forms.
Trees which do not succumb to disease pressure from these open wounds survive for years to come in this damaged state.
Utah State University Extension recommends wrapping trees in the fall with white tree wrap to prevent the bark of the trees facing southwest from warming too much in the late winter, helping to keep the bark cool, dormant and free of cracks and dead damaged tissue.
When wrapping a young southern magnolia back home, I tucked the corner of the wrap securely under itself to hold it in place.
Since our last frost is around April 15-20, wait to remove the wrap until after this date.
If the proper step is taken to limit winter cold injury to small trees, southwest injury and frost cracks can be avoided.