Mushroom spores, which are called mycelium, are actually present in many different soil types. They are even present in some indoor potting soil mixes that have not been sterilized at high heat. Although most mushroom spores will never grow into a mushroom, periods of ongoing rain and watering will make them appear. While mushrooms are unsightly, they pose no threat to the lawn, and you can remove them manually to prevent them from spreading.
Things You'll Need
Insert a shovel 4 inches from the mushroom, and dig down at least 5 inches to remove the mushroom from the ground. Gently place the mushroom into a plastic garbage bag so you do not disperse the spores, which will cause new mushroom growth. Repeat the process to dig up any remaining mushrooms.
Place pure nitrogen fertilizer into a fertilizer spreader, and set the dial on the spreader to dispense at a rate of 1 lb. per 1000 square feet of lawn.
Walk over the surface of the lawn in side-by-side rows to spread the nitrogen fertilizer.
Water the lawn lightly to soak the nitrogen into the soil. Nitrogen helps the soil break down organic matter faster, which eliminates the food source for the mushrooms.
To prevent mushrooms from regrowing, remove all decaying organic matter such as pine straw, mulch, and pet waste from the yard. In addition, remove any dead logs or tree stumps that provide food for the mushrooms.
Do not use slow-release nitrogen fertilizer. You want the nitrogen to act as quickly as possible to eliminate the mushrooms.