Green Ash Leaf Drop: Identifying and Managing Ash Anthracnose

Premature leaf drop on green ash (Fraxinus pennsylvanica) often signals ash anthracnose, a fungal disease attacking just after spring bud break. Cool, wet weather worsens it. Symptoms appear weeks later: large irregular brown patches on young leaflets along veins, deformation, severe drop in lower canopy where foliage dries slowly.

By the time you notice drop, the fungus has usually run its course—no treatment needed. It's an early spring disease; warm, dry weather prevents reinfection. Even heavy drop rarely affects overall health; trees typically push a second flush. Support recovery: water during dry spells, fertilize if growth is weak, mulch base.