A coworker recently stopped by my desk wondering what to do with the painfully persistent mushrooms popping up in their lawn after a tree was removed. Are they detrimental to the lawn or ingesting-curious children?
The short answer to both questions is largely, “No”. The fungi popping up in a lawn at the grave site of a stump are from a class of mushrooms known to eat decaying organic matter. They are actually a sign of healthy soil ecology. They are busy converting complex carbon chains into simpler forms useful to other organisms; they are not interested in anything living. Think of it like garden zombies that only attack other dead things, except saprophytic fungi are nothing like that analogy. If the fungi hyphae matts become too thick, it can inhibit plant growth, preventing air and water reaching turf grass roots. The best plan of attack is to cut back on irrigation, de-thatch the lawn, and increase nitrogen feeds.
As to children and mushroom foraging, I always caution caretakers to instill great caution in children to prevent ingesting any unknown material. Most fungi you are going to find in the lawn are harmless to humans, but there are a few that are not, so be careful. Just make ‘shroom for everyone to coexist, man and chill out a bit. All will be well.
Josh Steffen, Horticulture and Facilities Manager