Knowledgebase

Red oak issue? #923866

Asked January 22, 2026, 1:16 PM EST

Hi, I have a large red (or hybridized) oak in my yard and noticed this brown spot since the leaves started falling off this past year. I owned the home for only a year so not sure how long it has been there. Please let me know if additional photos will help. Thanks!

Montgomery County Maryland

Expert Response

It might be a spot of oozing sap (from an insignificant injury, potentially), though it's not clear what is causing the symptoms. Tree diagnostics can be tricky, in part just because it's hard to get close to many areas that need closer inspection. We recommend you have the tree evaluated by a certified arborist if this symptom is concerning or if it worsens, or if the tree develops additional symptoms later this spring/summer. Arborists can't always treat or cure every condition, but they can help to narrow-down a diagnosis and look for sources of tree stress that might be able to be alleviated.

Miri
Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied January 22, 2026, 4:29 PM EST

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