Heavy rains, prolonged rainy periods, or excess watering often encourage the growth of mushrooms (toadstools) in home lawns and other turf areas. Most often, the mushrooms will appear randomly across a new lawn because of the extra water required to get the sod to root in. Once the moisture in the soil reduces, the mushrooms should stop appearing. Since young children and pets may be tempted to eat mushrooms, remove the obvious fungal structures by raking, mowing, or hand picking to avoid the possibility of poisoning or illness.