Mushrooms appearing in a yard are the visible, fleshy fruiting bodies of a much larger fungal organism living beneath the soil. These fungi, existing as a network of microscopic threads called mycelium, are generally not a sign of lawn disease but rather a decomposing ecosystem. They are nature’s recyclers, actively breaking down buried organic matter and releasing nutrients back into the soil, which benefits the surrounding grass. However, because their sudden appearance can be unsightly, and certain varieties pose a toxicity risk to pets or small children, many homeowners choose to remove them. Effective removal requires immediate action to eliminate the visible nuisance and long-term changes to address the fungi’s underground food source.
Immediate Removal of Visible Mushrooms
The quickest way to eliminate the immediate risk and eyesore is through physical removal of the mushroom caps. These visible structures are temporary and exist solely to produce and release reproductive spores. Removing them before they mature and shed spores is the primary goal.
Hand-picking the mushrooms while wearing gloves is the most direct method, ensuring the entire cap is removed from the soil surface. Alternatively, mowing over the area can knock the caps down, but it is essential to use a mower with a bagging attachment. Mowing without a bag will chop the mushroom tissue and scatter millions of spores, promoting future growth. All collected material should be placed in a sealed bag and disposed of in the trash. Do not add these materials to a home compost pile, as the fungal spores can survive and spread.
Eliminating the Underlying Food Source
Addressing the long-term presence of mushrooms requires cutting off the underground mycelium’s primary food supply. The fungi responsible for lawn mushrooms are saprophytic, meaning they thrive on decaying organic materials buried beneath the turf. This organic matter can include old tree roots, buried lumber or construction debris, or excessive accumulations of dead grass clippings and leaves.
One of the most common food sources is a thick layer of thatch, which is a tight, interwoven mat of dead and living grass parts near the soil surface. Dethatching the lawn removes this layer, eliminating a significant nutrient source and improving air circulation to the soil. Similarly, core aeration, which removes small plugs of soil, helps alleviate soil compaction and improves drainage. Compacted soil retains water for longer periods, creating the moist conditions fungi need to thrive.
Adjusting watering practices is also a highly effective long-term strategy, as fungi require consistent moisture to grow and fruit. Instead of frequent, shallow watering, homeowners should switch to deep, infrequent irrigation. This practice allows the top layer of soil to dry out between waterings, making the environment less hospitable for fungal development while encouraging deeper, healthier grass roots. Watering the lawn early in the morning ensures that the grass blades and soil surface dry completely by midday. If the problem is localized, digging up and removing any suspected buried organic matter, such as old tree stumps or wood pieces, will permanently remove the fungi’s food source.
Specialized Treatments and Fungicides
While cultural practices are the most effective long-term solution, some may look to applied substances for immediate treatment. General commercial lawn fungicides are often ineffective against the saprophytic fungi that produce lawn mushrooms. Fungicides are typically formulated to combat parasitic fungi that cause turf diseases, not the decomposers that live on dead organic matter. If a fungicide is used, it should be one specifically labeled to target the responsible fungus, such as those that treat the fairy ring condition.
Common home remedies, such as solutions made with dish soap, baking soda, or vinegar, can sometimes kill the visible mushroom cap. Dish soap may work by breaking down the mushroom’s outer membrane, and baking soda or vinegar alters the localized pH. However, these solutions do not penetrate the soil to kill the extensive underground mycelium and can potentially harm the surrounding grass if applied incorrectly or at high concentrations.
A more targeted approach involves using a high-nitrogen fertilizer, which is not a fungicide but an indirect treatment. Applying nitrogen can stimulate the activity of soil microbes that accelerate the decomposition of the organic food source. By hastening the breakdown of the buried wood or thatch, the nitrogen fertilizer effectively removes the food supply for the fungi, eventually preventing the mushrooms from fruiting.