Japanese Maple Bark Peeling: Sooty Bark Disease and Lichen—Water, Insecticide, Monitor

Bark peeling everywhere with green moss/lichen underneath suggests sooty bark disease (fungus from drought stress) plus lichen colonization.

Immediate Care

• Water deeply 30+ min, 1–2x/week (don’t saturate).
• Remove competing plants (especially grasses) from root zone.
• Ensure good drainage.

Sprays (Summer Caution)

• Horticultural oil may burn in heat—avoid.
• Permethrin or malathion can reduce lichen/moss and secondary insects.

Critical Threshold

If bark peels all around trunk (girdling), tree will likely die. Monitor for callus formation; if none, tree may not survive.

Japanese maples in non-native climates often live 60–75 years.