wondash

I've got mushrooms growing everywhere in my mulch beds. Big ones. Little ones. Flat ones. Tall ones. Part of the problem is all the rain we've had this past spring. Also, some parts of my property have poor drainage or are heavily shaded. Does anyone know how to prevent them from growing? Grass and weed killer seems to have no effect, but I think it may have caused them to mutate into larger versions!