Black leaves on maple tree

Asked June 12, 2020, 5:45 PM EDT

I have one maple tree in my yard that for the last couple years has had it’s leaves turn black and fall off. I can not see any insect damage on the leaves, even ask one of my nephews MSU trained in animal husbandry and associated farm background what he thought. He concurred no insect damage he could see. I am concerned that I could loose this tall maple beside the house. I also don’t want to see whatever is it’s issue to spread as there are a lot of maples around me on my as well as adjacent properties. I am also very close to National forest property. We don’t need any more tree issues in our forests.

Wexford County Michigan

3 Responses

It looks like you have a recurring issue with a fungal disease called Maple Anthracnose. It is particularly bad this year in most of Michigan. Weather conditions can make it worse in some years than in others. I suspect that in your case it may have something to do with the site that the tree is in and/or you have just had bad luck with spring weather for the last few years. If you rake up the fallen leaves and destroy them by burning or burying them, it will help some. Also, I would recommend giving the tree a little fertilizer and making sure that it gets some irrigation during dry periods this summer. Those actions will decrease the physiological stress of the tree and allow it to recover and fight off the infections better in the future. It this is a mature tree that hasn't ever been pruned, you might want to consider having a certified arborist remove some limbs to improve the air flow in the canopy. Increased air flow will allow the leaves to stay drier in the spring and reduce the infection by the anthracnose fungus. You can find a certified arborist in your area using this online search tool: https://www.treesaregood.org/findanarborist
And you can read more about anthracnose and another similar disease by reading this MSU Extension article:
https://www.canr.msu.edu/news/maple_leaf_blister_and_anthracnose_two_foliar_diseases_that_can_appear...

In reguardada to the anthracnose fungus, I have an additional question. If after racking up the leaves would you recommend treating the area under the trees drip line with a fungicide? If it would help to stop the transmission through the ground from one year to the next, I would be more than willing to spray the ground as I have noticed it spreading to some adjacent trees. If it would be helpful what fungicide was you recommend and how often and when would it be best to apply.

i greatly appreciate your response and hope I am able to deter if not completely get rid of this nasty fungus. The thought of having to take out 3 or more of my trees does not make me happy as they are more than likely about 25-30 years old and hopefully have more years left to them.
thank you again
Patti






The fungus is particularly bad this year because of the weather. Raking up the leaves really is the best thing that you can do to reduce next year's infection. For the long-term health of the trees I would again recommend that you consider having them pruned by a certified arborist to increase air flow through the canopy. The anthracnose is not life-threatening to the trees and as long as they are otherwise healthy, I'm sure they will have many more years in them.