Black Spots on Maple Trees

Asked October 12, 2020, 11:47 PM EDT

Hi, we put in 4 Maple Trees (I believe they are Autumn Blaze Maples) late last fall. They did well through the winter and Spring. In late spring we had a bout with June Bugs/Japanese Beetles. We put out some beetle bags for a while and captured quite a number of beetles and they seemed to go away with no further damage to the leaves or trees. Throughout the summer I noticed a few leaves being eaten but not a lot of them and the leaves were not completely eaten, they were mainly towards the tops of the trees. It did not seem to be a major issue. However, last week I noticed on almost all the leaves of all 4 trees these black spots. I have attached 3 photos showing you what I'm seeing. Is there anything I need to do to address these spots or the health of the trees? Or since we're close to the leaves turning color and dropping is it only a cosmetic type of issue? I appreciate any advice you may have. Thank you

Guilford County North Carolina

1 Response

It's most likely a fungal leaf spot because of the weather that we've had and they are very common in this area. What we usually recommend is that you clean up and remove any infected leaf litter so that the fungal spores are removed from the area to prevent reinfection, and maintain proper watering, mulching, and fertilizing (if needed) to give the trees optimal growing conditions to help them be able to fight off issues like this. You are absolutely right that it is the end of the growing season and they are about to defoliate and it is mainly a cosmetic issue. Excessive early defoliation several years in a row might be an issue, but these trees have had plenty of sunshine and water this year to store up enough energy for the dormant season so the overall health of the trees won't be affected.