Mushrooms can suddenly pop up in lawns throughout the summer, often appearing overnight. Typically, most of the mushrooms are more annoying than problematic however some are toxic if eaten by animals and children.
While mushrooms are the part of the fungus we see, they are just a way to produce spores for the main part of the fungus which remains hidden in the soil. Although removing the mushroom may improve the appearance of the lawn, and temporarily keep the mushrooms away from animals and children, the fungus living in the soil will produce more mushrooms when conditions are right. Identifying and removing the source of food for fungal growth will help eliminate the mushrooms.
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Mushroom producing fungi feed on organic matter in the soil, which could be anything from thatch between the soil and green grass, decaying tree roots, or lumber left over and buried in the lawn during home construction. In many cases, once the organic matter has been decayed, the mushrooms will disappear, while others may come back year after year in the same location.
Mushrooms can easily be raked or kicked over, gathered and discarded in the trash or buried in the compost pile.
If excessive (more than ½") thatch is present it is important to determine why the thatch accumulation is present and dethatch as described in the following publication: https://www.extension.purdue.edu/extmedia/AY/AY-8-W.pdf. Also see a related article on slime mold by clicking on the image below.