Walnut Tree Fungus

Asked April 30, 2020, 1:52 PM EDT

Want to know if this is something to worry about. I believe this is a Black Walnut tree. The orange substance is very foamy.

Marion County Oregon

1 Response

Hi: essentially what is happening is that there is tree sap leaking from the tree onto the bark and this nutrient-rich sap is attracting microorganisms which are feeding on it and causing the colorful result. I cannot be 100% sure, but I think I see in the one photo some evidence of sapsucker activity, and these birds drill parallel lines of hoes in the bark of trees. It's very common for these holes to reach the vascular tissue of the tree and be the source of the leak of these fluids. The link below from Cornell University provides more information:
Given the size of the tree and the possible presence of the sapsucker activity, you might consider having an arborist confirm th source of the sap flow and provide an opinion on the integrity of the tree for you. You can find a qualified consulting arborist at the PNW International Society of Arboriculture website: