Ash tree leaves falling off? Chances are you've got an anthracnose fungus that can stress your tree and ruin its appearance.

There are several treatment options that Majestic will review with you. In all cases be sure to rake up the infected leaves and dispose of them as the fungal spores can survive over the winter on infected leaves.

Ash Anthracnose Fungus Effect on Leaves.

Parasitic Diseases of Specific Trees http://www.ext.nodak.edu/extpubs/plantsci/hortcrop/pp697-2.htm#Ash