Ask a Consulting Arborist Q&A: Leaf, Seed, and Flower Concerns

Q: Last fall, my maple tree had quarter-sized dark spots on the leaves. What are they from?

Wednesday, December 30, 2015  

Q: Last fall when the leaves fell from my maple tree, there were quarter-sized dark spots on the leaves. Can you tell me what causes this and what to do to return my tree to a healthy state?

A: If the spots are black in color, tar spots is likely the culprit. Trees growing in moist, sheltered locations seem to be more affected. You can find information on various websites, including, which is a Michigan State Extension page. A key cultural practice will be to rake fall leaves and destroy them, thereby reducing new infections the following spring. Also, fungicide treatment is typically unnecesary and wasteful since tar spot is not fatal to the tree. You will learn to live with some spots, and occasional early leaf drop, but your concern indicates you will be happy to accept these few negatives along with the myriad of environmental, economic, and social benefits of trees. Best of luck.


Responder: David Jahn, RCA #425, Des Moines, IA