Sunscald damage on maples trees

Asked August 12, 2019, 1:40 PM EDT

The bark on my maple trees appears to have been damaged by sunscald this year. There were no problems in the previous years. Now the bark is damaged and the trees are losing the leaves as well. The trees were not painted. What would be the correct course of action now: clean the damaged areas and apply grafting wax, clean and paint now or late fall, or do nothing except watering and maybe some fertilizing? Thank you for your advice.

Howard County Maryland abiotic issues trees poor planting and care sunscald on maple bark not sunscald

3 Responses

We are happy to help, but need some additional information from you, and even better, a few photos of what you are seeing as well. An overall shot of the tree, a look at the damage and one of the trunk area at the soil line would be helpful.

How old is the tree? Any changes to the site? Digging? Vehicle traffic? Chemical applications to the lawn? Any info you can supply will help us to help you.

Photos and information can be attached directly to this reply, using the Choose File tabs below.


There weren't any changes to the site. I don't know the age of the tree , but probably 10+ years. Pictures are attached.

Thank you.

We are not sure what areas of the trunk that you are most concerned about, but we do not see sunscald. We do see issues are of concern however that would lead to decline.
We don't recommend painting bark or applications of wax, tar or any other covering to wounds anymore.
The biggest issue that we see is that the tree was planted (or perhaps mulched) too deeply, which can kill a tree over a long period of time.
It shouldn't go into the straight into the ground like a telephone pole. You should be able to see a gentle flare/widening where the trunk meets the roots.
You can see more about this by clicking on 'planted too deeply' at this link:
You can try to uncover the root collar or hire an arborist to do so if the tree is not too far gone and is important to you.

Look at the mulching too deeply and girdling roots as well.

Look at lichens too, which are green or grey growths that you may have concern about but that are harmless.

We have a recent blog post about the cultural needs and problems of Japanese Maple that should be helpful:

We can't see how much of the crown of the tree is affected or how much dead wood there is. Dead wood can be pruned out at any time. You can test for which branches are dead by bending branch tips. If they snap or if the tissue beneath an area you scratch with your fingernail is dark, it is dead. (You can also wait until next year and see what leafs out.
Here is our pruning information, which will tell you how to make the best cuts that will heal themselves and present best practices:

Here too is our page that helps homeowners decide when it may be time to remove a tree: