What Causes Mushrooms to Grow in My Yard?

Overly Moist Conditions

• Mushrooms and other fungus thrive where there is plenty of moisture. They are similar in structure to mold and mildew and, just like in bathrooms, anywhere they can find warm and moist conditions, mushrooms are going to thrive. This can be an issue in areas that receive several inches of rain at once, or in lawns that have poor drainage. In the case of excessive rainfall, there isn't much that can be done other than killing the mushrooms that appear. Drainage issues however can and should be fixed to avoid not only the re-occurrence of mushrooms but also flooding concerns.

Composting Material

• Yards often contain decaying organic material such as dead leaves, grass clippings and composting material. When coupled with moist conditions, this provides an excellent breeding ground for mushrooms and toadstools. Even dry areas of the country can experience mushrooms when they have a little bit of rain and the right growing conditions. Leaves should always be raked up in the fall, and grass clippings should be removed, bagged and discarded when mowing.

Dead Wood

• Just like composting material, dead wood supplies fungus with the growing material it needs to thrive. Dead branches, logs and even excess bark on the ground will nourish the surrounding soil and make it more moist, leaving the door wide open for the formation of mushrooms. Logs, branches, sticks and bark should be removed from yards and properly disposed of to avoid this issue.

Spore Propagation

• One of the most common reasons that mushrooms can take hold of a yard and keep returning is due to spore propagation. Each mushroom will house thousands of tiny spores. If these mushrooms are disturbed, the spores will be spread throughout the general area and continue to be an issue. For example, mowing over a mushroom will shred the material and release the spores not only on the ground but in the air, where they can travel. Kill mushrooms using anti-fungal spray and don't handle them to prevent the spread of their spores.