Maple Tree Bark Cracking - Ask Extension
Hi, I recently noticed the bark on my maple tree is cracking and seems to be peeling away from the tree. It is happening on all sides of the tree. Is ...
Knowledgebase
Maple Tree Bark Cracking #622518
Asked April 09, 2020, 9:10 AM EDT
Hi, I recently noticed the bark on my maple tree is cracking and seems to be peeling away from the tree. It is happening on all sides of the tree. Is this a sign that it is unhealthy or dying? If so, is there anything that can be done to save it? The grass around the tree also appears to be impacted. The tree currently has new buds and we have not noticed any problems with the leaves in previous years, but this is the first year we have noticed the bark.
Oakland County Michigan
Expert Response
Hello,
Thank you for contacting Ask and Expert.
Maple trees have thin bark, which makes them susceptible to frost cracks, especially on the south side of the tree. Frost cracks are vertical cracks in the stems of trees. These happen when there are rapid temperature fluctuations. On warmer, sunny days in the winter, the bark will warm up, which causes the cells to expand in the bark and wood directly below the bark. Then if temperatures drop very quickly, the bark cools and contracts. The wood under the bark does not cool as quickly, causing the bark to split. There is some research indicating these frost cracks happen at sites of previous injury. These frost cracks often grow tissue over the crack, which is called callus. In the photo I see a split that may have happened in past years, and has not callused over. These splits can provide access for pathogens such as fungi which can lead to decay.
Frost cracks can be prevented by wrapping the trunk in a light colored tree wrap in the fall. This wrap needs to be removed as soon as danger of extreme cold in the spring has passed, as they can harbor insects and diseases, and inhibit growth if left on. For now, it is important to support the health of the tree by preventing wounds from lawn equipment, etc., and by proper mulching. Mulching is a good way to keep lawn equipment away from tree trunks and provides a better environment for the tree's roots. However, improper mulching can kill a tree. Always keep mulch away from the trunk and keep the depth to about 3 inches. You may want to water the tree if there is a long dry spell, and avoid over-fertilizing.
As far as the grass goes, maple trees have lots of shallow roots that compete with grass, causing thinning and bald areas. This is another reason that mulching around trees can be a good idea. If you do decide to mulch around the tree, remove the existing grass carefully so as to avoid damage to the root system. For more information on frost cracks, I have attached a short article:https://extension.umd.edu/hgic/topics/frost-cracks-sunscald-growth-cracks
I hope this is helpful.
Ruth
Thank you for contacting Ask and Expert.
Maple trees have thin bark, which makes them susceptible to frost cracks, especially on the south side of the tree. Frost cracks are vertical cracks in the stems of trees. These happen when there are rapid temperature fluctuations. On warmer, sunny days in the winter, the bark will warm up, which causes the cells to expand in the bark and wood directly below the bark. Then if temperatures drop very quickly, the bark cools and contracts. The wood under the bark does not cool as quickly, causing the bark to split. There is some research indicating these frost cracks happen at sites of previous injury. These frost cracks often grow tissue over the crack, which is called callus. In the photo I see a split that may have happened in past years, and has not callused over. These splits can provide access for pathogens such as fungi which can lead to decay.
Frost cracks can be prevented by wrapping the trunk in a light colored tree wrap in the fall. This wrap needs to be removed as soon as danger of extreme cold in the spring has passed, as they can harbor insects and diseases, and inhibit growth if left on. For now, it is important to support the health of the tree by preventing wounds from lawn equipment, etc., and by proper mulching. Mulching is a good way to keep lawn equipment away from tree trunks and provides a better environment for the tree's roots. However, improper mulching can kill a tree. Always keep mulch away from the trunk and keep the depth to about 3 inches. You may want to water the tree if there is a long dry spell, and avoid over-fertilizing.
As far as the grass goes, maple trees have lots of shallow roots that compete with grass, causing thinning and bald areas. This is another reason that mulching around trees can be a good idea. If you do decide to mulch around the tree, remove the existing grass carefully so as to avoid damage to the root system. For more information on frost cracks, I have attached a short article:https://extension.umd.edu/hgic/topics/frost-cracks-sunscald-growth-cracks
I hope this is helpful.
Ruth
