Black spots on maple leaves

Q. Why are there tar-like spots on my maple tree leaves?

A. Black spots sometimes appear on the leaves of maple trees from mid-June to mid-July. The spots are a fungal disease called Maple Tar Spot (the spots look just like they sound). The spots do not cause damage to the tree and are only cosmetic so no control is necessary.

If the Tar Spots continue for several years and the disease continues to bother YOU, it can be controlled by spraying. The timing of this spray is very important – it must be done at the beginning of May and again at the beginning of June. Spraying outside this timeframe won’t have any effect on controlling the fungus that causes the spotting.

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Answer Provided By ...

Warren Liken

With more than 40 years in the Green Industry, Warren offers a wealth of experience, passion, and expertise. He's one of a handful of Certified Arborists in the Great Lakes Bay Region, as well as an active member of the International Society of Arboriculture’s Michigan chapter. You can count on Warren and Bay Landscaping to solve your tree and plant issues.