Question
Fairy rings have taken over our back lawn.  Outside of digging the entire lawn up, are there any other ways of ridding ourselves of these mushrooms?

Answer
Good afternoon Susan:
Fairy ring appear in various ways in the lawn. Perhaps the most common, especially in spring, are circles or arcs
of dark green, lush, fast growing grass. These rings are most commonly between 2 and 15 feet in diameter.
Mushrooms or puffballs may appear under wet conditions in this same ring pattern. In some cases, a ring of
brown or dead grass may appear.
Fairy ring fungi are not attacking the grass but are breaking down organic matter in the soil. Nitrogen is released,
that the grass above may use, causing the green ring. In some cases, the mycelia of the fungus gets very dense
and inhibits water movement into the soil. In those cases the grass in the arc may turn brown. Mycelia may also
deplete soil nutrients and produce toxic levels of hydrogen cyanide. The mushrooms that appear after rainfall are
the fruiting bodies of the fungus.
The organic matter that the fairy ring breaks down can be old tree stumps, roots, logs, lumber, and other larger
pieces of organic material in the soil below the lawn. Once this material is depleted, the fairy ring will disappear.
This may take several years. A number of  fairy rings may appear relatively close together. When this occurs, it
becomes noticeable that fairy rings do not cross each other, as fungus activity ceases when fungi from different
rings contact each other.
There are several options for managing fairy ring. When establishing a new lawn remove tree stumps, large roots,
and construction lumber prior to planting. When renovating an area that previously had fairy ring, be sure to
blend all the soil together, as different fairy ring fungi will attack each other. If several rings are visible at the time
of renovation, collect the white mycelia from each and mix it together, then spread it over the soil and work it in.
Lawns watered and fertilized on a regular basis tend to have fewer problems with fairy ring. In addition, large
quantities of water may be pumped into the soil in and around the rings using a root-feeder attachment to a
garden hose.
Mushrooms and puffballs not associated with fairy ring may also appear in lawns, especially after heavy rains.
These are also feeding on organic matter in the soil. Some may have a foul odor, some may be poisonous. As
with fairy ring, eventually the food source will be depleted.
If many mushrooms appear in an area, you must dig up and remove the buried organic matter. If children or pets
contacting the mushrooms are a concern, break or mow off the mushrooms when they first appear.
Although I have not tried this product, I have heard that it shows promise. Go to the website:
http://www.galaxymall.com/product/landscaping/
Have a good lawn!
Floyd McMahon