Maple Tree Multiple Spot Syndrome: Insect, Fungus, and Algae Complex

Mary's maples show white spots and larger black spots on leaves, greenish spots on trunks.

Expert Differential Diagnosis

Steve provided a rainbow of possibilities:

• White leaf spots: Likely scale insects (raised on surface)
• Black leaf spots: Anthracnose fungus (especially after heavy rain)
• Green trunk spots: Algae or lichens (shaded trunks, not major health threat)

Management Strategies

• Large trees: chemical management often impractical
• Sanitation: Rake and destroy (burn if allowed) fallen leaves late winter/early spring BEFORE new leaves emerge—reduces insects/diseases
• Photo submission for confirmation (one per question with current system)

Key Insight

Multiple simultaneous issues on maples are common. The sanitation practice is the most universally beneficial and feasible intervention for large trees.