Green Moss on Maple Trunk: Harmless Lichens, Not Disease

Michigan maple has green moss/mold on trunk to first branches; some leaves changing color. Problem?

Identification: Lichens

Not moss/mold. Lichens are air-fed (not parasitic), thrive in sun on exposed bark (winter leaf-off or thin canopies). Indicate, not cause, decline.

Management

• No action needed – not harmful
• If removal desired: copper fungicides (ball moss label) or baking soda home remedy
• Leaf color change likely weather-related; not concerning if tree watered during dry periods