Leaf Spot – On Poplar, Maple, Sweetgum
Q: I have a sweetgum tree in my back yard that appears to be dying. The leaves have all turned color as though it was fall and they have black spots on them. What is this?
A: I’ve seen similar symptoms on maple, poplar and flowering cherry. Leaf diseases do not affect all trees but it is very noticeable on the ones it does strike. I’m sure the weeks of hot and humid weather in July and early August caused the problems.
The problem on your sweetgum tree is either sweetgum anthracnose, Gloeosporium nervisequum, or sweetgum leaf spot, Cercospora liquidambaris.
Similar fungi are on the other trees I’ve mentioned. All are exacerbated by wet weather but probably won’t kill the trees.