Some species of mushrooms, including the panaeolus cinctulus, can be dangerous, so it's important to prevent them from growing in your yard. Children and pets often investigate plants by eating them. The paneaolus cinctulus can cause severe reactions in both kids and pets. Mushrooms can be difficult to remove once they're established, as each mushroom can release hundreds of spores, which quickly become new mushrooms. It's best to prevent mushrooms from growing in the first place.
Mushrooms will form on anything that is decomposing, including wood or tree roots. Do not store old lumber in your yard, and do not use wood to line your flowerbeds or compost piles. Improve the aeration in your lawn by renting a thatching machine and using it at least once per year. Look for depressed or low spots in your yard that tend to collect water. Work with a landscaping company to fill and compact these areas with well-draining soils so that no standing, boggy water forms on your property. In general, avoid over watering your lawn to prevent swampy patches from forming. This may be unavoidable if you've just planted your lawn, as the tender grass needs a lot of water to grow. Rest assured that any mushrooms that form during this stage will starve and die once your lawn is fully established.
If your grass is healthy and growing well, it will out-compete and outgrow mushrooms and mushroom spores that land on your lawn. Apply a quick-release nitrogen fertilizer to your lawn once per year. Nitrogen will encourage decomposing matter to decompose quickly and will help your lawn to grow. If your neighbors have mushrooms in their yards, talk to them about removal methods. By plucking the caps from mushrooms, they can significantly reduce the number of spores that wend their way into your yard.