Mushrooms in the Lawn
Mushrooms that appear in grassy areas rarely do damage to turfgrass. They can be unsightly, however, and fairy-ring mushrooms, in particular, can create a darker green ring in the grass where they are actively growing.
Since many mushrooms are also poisonous, they may need to be removed if young children or pets are present who may eat them. Mushrooms are the fruiting bodies of a large fungal network beneath the surface of the soil. Thus they are extremely hard to eradicate. Mushrooms themselves appear after wet periods, normally in the spring but often in the summer with sufficient rainfall. The fungal network that produces them is generally beneficial, feeding on decaying organic material and releasing it into the soil where the grass can often utilize it.
To quickly remove undesirable mushrooms, handpick or mow them off. This will not affect the larger organism but will keep them from dispersing their spores. Many species only produce mushrooms once a year, making this less of a chore.
Aerating the lawn to improve drainage and break up fungal mats can also be helpful. In the case of most mushrooms, removing dead roots and stumps from the yard will also remove the fungi’s food source. Using a quick-release nitrogen fertilizer can also help break down organic matter under the soil, once again removing the mushroom’s food source. There are currently no fungicides available for non-commercial use that control mushrooms.