William Hogan | 8/10/2011 6:30:44 PM
With the advent of frequent rain showers and at least a break in the severe drought we have experienced for the past months, we are seeing an abundance of structures appearing in the lawns. Botanists call these structures basidiocarps. Most people call them mushrooms. They may appear as a single object, in groups or clusters or in a ring. They may vary in shape, color or texture. These are the fruiting structures of fungi that inhabit the soil. The fungi are always there. They live under the lawn grass. They feed on organic matter under the soil surface. When the weather is hot, humid and rain showers are frequent, they will send up these structures to disperse their spores. These structures are especially common when these conditions follow a period of prolonged dry weather.
These fungi don’t parasitize the grass or other plants in the lawn. Occasionally, the lawn grass in their close vicinity will change color. This is due to the fungi using soil nitrogen to produce the mushrooms. This discoloration is usually very temporary. If the mushrooms bother you, rake them up or mow the grass. Several fungicides are labeled for use in the home lawn. Applying these prior to the emergence of the mushrooms might prevent their occurrence. This is usually more trouble and expense than it is worth because of the infrequency of their appearance. It is also difficult to get the fungicide down into the area where the fungus is growing.
One word of encouragement - mushrooms seldom occur in a poorly maintained lawn. The fungi tend to grow well under the same conditions that favor good lawn growth.
The LSU AgCenter and the LSU College of Agriculture