Oak bark peeling after drought in St. Louis
Peeling bark over a tan, silver-grey or dark crust can be more than a surface blemish. An arborist should assess the cause and the risk from the affected tree.
Updated November 2, 2026
What might be happening?
MDC describes Hypoxylon canker outbreaks following severe drought. Later signs include bark falling away to reveal a dusty tan mat that becomes silver or grey; older infections may look black, with brittle decaying wood.[6]
What to tell the arborist
Tell us about recent drought stress, root damage, construction and branch dieback. Note where the bark has fallen away without pulling off more bark or standing below damaged branches.
The next step
Arrange an assessment of the tree and any nearby targets. A care plan for other trees can address avoidable stress and drought watering, but it must be separate from the decision about the affected tree.
What not to assume
MDC states that there is no treatment once Hypoxylon symptoms develop. Do not rely on feeding or an injection as a cure; infected trees in areas used by people may need removal to prevent falling-limb damage.[6]
This is general guidance, not a diagnosis. Your arborist confirms the cause and treatment suitability on site; some concerns also need laboratory confirmation.
Immediate danger from a tree or hanging limb? See 24/7 storm help. Stay away from downed lines and anything touching them; call the utility for electrical hazards and 911 for injuries.