I have an English walnut that is approx. 5-6 years old. There is a White fungus growing in the collar from a branch I removed. Is it harmful or caused by moisture? The tree is 20 feet tall and is bearing nuts. In the state of Wisconsin.

Tree showing white fungus where branch removed

  • Are you sure that tree is only 5 years old? Boric acid (aka bug powder) is a cheap and extremely potent anti-fungal agent that won't hurt the tree; just give it a poof or two as needed.
    – dandavis
    Jul 19, 2021 at 23:17

1 Answer 1


I would put bleach on it to kill the fungus. A few applications would be good . If fungus gets into the trunk the tree will slowly die.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.