With the extended cloudy, rainy weather we have received recently, mushrooms have been popping up everywhere in water soaked lawns. Lawn mushrooms are the fleshy, spore producing fruiting bodies of a group of fungi which feed off decaying organic matter. This organic matter may be from rotting tree stumps or roots left in the soil, animal waste, old mulch, or decomposing grass clippings.
Since mushroom production is enhanced by damp, shady, highly organic environments, your best control is to target things you can do to help eliminate these conditions. Collecting or raking grass clippings, dethatching the lawn and replacing old mulch will help reduce the food source. Correcting drainage problems and soil aerification will improve moisture issues and selective pruning and thinning of trees will allow more light into shady areas.
There are chemical fungicides that will help remove existing mushrooms, but this is generally only a temporary fix as mushrooms will again appear as long as there is an abundant decaying organic food supply and favorable environmental conditions. Although unsightly, most of these mushrooms are not harmful to the turf. If they only occur during these extremely wet rainy periods I would not get too concerned about them, unless you have pets or small children they may be in contact with them as many are toxic to mammals if consumed.
Published September 21, 2009
Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. firstname.lastname@example.org