black spots on trees

Asked November 23, 2018, 8:15 PM EST

What are the black spots on many of our maple trees and what causes them? Are they a danger to the tree's health and survival? Is there anything we can do to eradicate them?

Kent County Michigan trees and shrubs gardening horticulture maples

1 Response

I am assuming you are referring to black spots on the leaves. This is a fungal disease known as tar spot, which is very common in our area. It is primarily a cosmetic issue and does not affect the long-term health of the tree. The best control for homeowners is to rake up and destroy all infected leaves in the fall. Mulching leaves is often not sufficient. The fungus can overwinter on fallen leaves and provide a source of inoculum to re-infect the trees for the next growing season. Please see the link below: