White Growth on Tree Trunk

Asked September 12, 2018, 10:26 AM EDT

I noticed a white growth on the north side base of a tree trunk yesterday. I can not say for sure how long it has been there, but this is the first time I noticed it. The tree is a mature bass wood with a 21 inch diameter trunk measured up about 4 feet. It is located in a wooded, heavily shaded area and we have recently had rain. Can you tell what this is and is it problem? I have attached a couple pictures.

Wayne County Michigan fungi

1 Response


This could be a slime mold that grows on wet mulch and on other wet plant material- http://msue.anr.msu.edu/news/unsightly_slime_mold_sighting_on_landscape_mulch

If it continues to grow up the trunk, even though the trunk has dried off, then submit samples to MSU Plant Diagnostic lab (with your pictures) -forms, fee schedule, and instructions are here- https://pestid.msu.edu

Or hire an arborist to come on site and examine the whole tree,and check for possible root or collar rot- www.treesaregood.org

I suspect slime mold because your picture appears to show some growing on the grass blades around the tree. Slime molds are harmless and disappear once the area is dry. Excess material can be gently brushed off( don’t scratch or cut into the bark).

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