Growths under ash trees
Some ash trees in the Iowa area have growths on the ground under the ash trees, apparent from the roots near the surface. They initially appear to be mushroom like, but then turn into a dark brown ugly semi-liquid. What are they and what should be done with them?
Certified GKH Gardening Expert
Without a photo I couldn't be completely sure, but it sounds like tar cap mushrooms. Once the area dries up significantly, they will go away on their own.
This article will help you to get rid of mushrooms in your yard, if you want to make this process faster: https://www.gardeningknowhow.com/lawn-care/lgen/eliminate-mushrooms-in-your-lawn.htm