Sick Maple tree - Ask Extension
I have a mature maple tree that has wide spread redish / brown spots on the leaves. Last fall it had some branches that didn't drop the leaves. This y...
Knowledgebase
Sick Maple tree #488181
Asked October 02, 2018, 3:41 PM EDT
I have a mature maple tree that has wide spread redish / brown spots on the leaves. Last fall it had some branches that didn't drop the leaves. This year most of the seeds didn't drop and the the leaves have more wide spread spotting. There is also a very large wound on the trunk. My thought is that a couple of springs ago there was some wide temp swings (freeze / thaw) and split the bark. Insects seem to be taking over under the bark so I removed the loose bark, the wound dried out the bugs disapearedand a scab formed along the edge of the bark. Ive attached photos for your inspection. How can I save this tree?
Ramsey County Minnesota
Expert Response
The vertical crack is probably sunscald, a common disorder of maple trees. It is caused by rapid heating and cooling in late winter. Read here:
https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter
Removing the loose bark may have helped. Prevention is the best tactic. Keep the tree well watered going into winter. Wrapping may also help. The above link gives details.
The spots are possibly one of several leaf spot diseases, perhaps phyllosticta leaf spot. Check this diagnostic site:
https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/maple/leavesspots.html
While leaf spot diseases are common and usually not threatening, they can be an indication of a tree under stress, or can weaken the tree. Early leaf drop and excess seeding are other signs of a tree under stress. I'd suggest you have your tree looked at by a certified arborist:
https://www.treesaregood.org/findanarborist
https://extension.umn.edu/planting-and-growing-guides/protecting-trees-and-shrubs-winter
Removing the loose bark may have helped. Prevention is the best tactic. Keep the tree well watered going into winter. Wrapping may also help. The above link gives details.
The spots are possibly one of several leaf spot diseases, perhaps phyllosticta leaf spot. Check this diagnostic site:
https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/maple/leavesspots.html
While leaf spot diseases are common and usually not threatening, they can be an indication of a tree under stress, or can weaken the tree. Early leaf drop and excess seeding are other signs of a tree under stress. I'd suggest you have your tree looked at by a certified arborist:
https://www.treesaregood.org/findanarborist
