When I'm dealing with toadstools (poisonous mushrooms) or mushrooms (fungi) in my lawn, I'm not a "fun-guy" to be around. In fact, about forty years ago, one of my daughters ate one. We made it to the ER ok, indicating that it was not a really bad poisonous one, otherwise they said we would have been too late!
I have a confession - my other daughter is the person with the lawn mushroom problem. Thus, I know that her conditions there match those in the referenced website. The front lawn had a tree removed a few years ago, but the roots remain. The mushrooms grow in rows that appear to radiate from the location where the tree was. I have not explored below the surface to verify my suspicion (we just pick them off). The mushrooms in the back yard, are likely due to the wetness resulting from water run-off from the driveway and the shading by the wooden fence on the south property line.
I will experiment first on my own lawn, since I have the same problem and similar conditions. I have a particular low damp spot in my yard that is near a 5 year old tree stump.
Mushrooms and stump
The grass grows taller and greener there than the rest of the lawn. I do not use a grass catcher (I don't fertilize, so I allow the clippings to decay and feed the lawn). I rake off most of the loose grass but I had never de-thatched. Previously I didn't consider the problem to be serious. Usually I would pull up the few large ones before mowing, but a few times they got chopped and spread. Now I get many small ones. *The website I referenced above said that they can't be dug out, but I have attempted to remove them along with the sod where there were. So far none have come back in the those locations, but they do in new places in the same area. After that, I de-thatched by vigorously raking the lawn. I am also trying to keep the grass short, but the long stretch of rain has made that difficult. I cut out many of the dead roots (see below).
Removed tree roots
I chose to remove sod from my center garden path (and will be replaced with mulch over weed cloth so I won't have to mow it anymore) to fill in. For additional sod, I plan to dig some from a spot for a wildflower garden. I have various other places, but if I run out, I'll use dirt and grass seed.
Eventually I plan to remove the stump and the rest of the roots (the mushrooms tell me where they are). I may follow up at a later time as to whether my efforts make it better, worse, or have no effect.
Does anyone else have a topic for the next tip? - Mr. C.