Questionable fungus in yard

Asked August 9, 2018, 4:34 PM EDT

Hi, Last year, I noticed a little patch of fungus in our yard. It was right by our walkway and near a tree in the front yard. I foolishly mowed right over it. No surprise, it came back. This cycle happened a couple times. This year, I saw it there once but now the same thing is closer to our house. There are a few other spots of fungus in the front yard area elsewhere but the largest spot is near the house. Coincidentally (or not) our tree started yellowing in some branches. I don't know what kind of tree it is either. Is this aspen tree fungus? Any idea what it is and what to do and whether it might be impacting our tree? The third photo shows the approximate locations. Just to the right in foreground is where the patch first started. The picture near the house is to the right of the porch. Thanks! Derek

Lane County Oregon

1 Response

Thank you for your question, Derek. You are dealing with a couple of different, and probably unrelated issues. First, the tree may be suffering from a soil pathogen (verticillium wilt) which causes flagging (branches dying), that can be diagnosed through soil testing, as well as inspection of the 'veins' of the tree, after cutting off the branch. However, there are several other conditions which affect aspen trees in Oregon, and they could not be diagnosed without observing the leaves. For that, you would need to go into the Lane County Extension office while a diagnostician is there. (Contact info:

The other two problems are likely caused by different fungal states. The large one near your foundation appears to be a slime mold, and the patches may be fairy rings, both of which are explained in the following article: