Q: I have large white mushrooms all over my yard. The grass is mostly dead or dying. Did the rain bring these things? What can I do?
A: The photos you brought me are similar to the ones I took of my neighbor’s yard. This is called “fairy ring.” Although the name sounds cute the problem is far from amusing. The mushrooms are living on decaying material. The material may be dead and dying grass, organic amendments added to the soil before the grass was put down, dying tree roots or landscape debris buried under the soil. The first step is to remove the mushrooms immediately by hand picking them and placing them in a trash bag. The soil may be compacted and will need to be aerated. A pitch fork or metal rake can be used to break up the soil. Attached is a publication by the University of Florida regarding fairy ring which will include fungal applications. Remember fungicides work best to protect the grass rather than cure the problem. Always read the directions on the label of any pesticide before application. Most important is to be sure to identify the problem before applying any chemical – that is the law! It may take as many as five years for the mushrooms to run out of their food source so be vigilant and patient. http://edis.ifas.ufl.edu/LH046