What is causing my maple tree to lose its leaves?

Asked July 31, 2015, 5:17 PM EDT

My 10-year-old maple tree has been losing leaves from the center of the tree out. The attached picture is a good leaf on the left and two diseased leaves - center and right. Do not see bugs, scale, or aphids. Almost looks like leaves are turning fall color, but orange is more like dull rust. Is it a fungus wilt?

Dakota County Minnesota

1 Response

Many things can account for the symptoms you have described. Some of them are described in this publication: Maple Decline: Various Factors

Asking a forester or certified arborist to assess the tree's health onsite is probably the best way to determine what's causing the problem.

In the meantime, see if you can rule out verticillium as a possible cause by reading the following publications. Norway maples are especially susceptible to this disease.

If you suspect verticillium, bring this to the attention of an arborist or submit a sample to the University of Minnesota Plant Clinic to determine whether the disease is present, Here is the link to the Plant Disease Clinic.