Leaves turning black

Asked May 28, 2020, 4:35 PM EDT

Hello, I have 3 maple trees at my house. Last fall I noticed some of the leaves has black spots on them. I had hoped they would not come back after the trees lost their leaves. As they came back this spring, the spots are back and some of the leaves are turning all the way black. Can you help as to what I causing this? I’d hate to lose our trees.

Ottawa County Michigan

1 Response

Tar spot is a common occurrence in Michigan but does not usually exhibit its pronounced self until later in the year, fall. Read more here: https://www.canr.msu.edu/news/black_polka_dots_on_maple_tar_spot

Maple anthracnose is much more common at this time of year. Anthracnose can be a fairly common spring disease on maple leaves in some years. There are several different fungi that cause anthracnose. One of the fungi (Kabatiella) causes newly developing leaves to shrivel and turn black, while older leaves develop dark brown lesions along the leaf veins. Fungal leaf diseases do not often threaten the long term health of the tree, but can be severe under certain conditions. Wet springs, and much of Michigan has seen a wet spring this year, usually cause increases of fungal diseases. Read more here: https://ag.umass.edu/landscape/fact-sheets/maple-anthracnose

If it becomes worse, the recommendation is to involve a Certified Arborist, first to
be sure that the correct diagnosis it is indeed anthracnose, and second for your peace of mind going forward. Find one or more Certified Arborists in your zip code at www.treesaregood.org Go to the Find an Arborist tab. Arborist evaluations are not expensive and where you can learn exactly what is going on in your tree.

Good luck!