A variety of fungi can grow in lawns without harming the turf. Many decay (break down) organic matter and recycle nutrients back into the soil, or form symbiotic relationships with live plant roots as mycorrhizae.
There is no practical or permanent way to eliminate mushrooms. They do not need to be removed to protect lawn health, and using a fungicide will not get rid of them. Mushrooms tend to appear after wet weather and will disappear on their own in time.
Pluck mushrooms and dispose of them if a child or pet might try to eat them. Never assume lawn mushrooms are edible.
Mushrooms in lawns
Mushrooms are fruiting bodies – reproductive structures, similar to the seed pods of plants – that are typically short-lived parts of the fungus. Not all fungi produce a recognizable mushroom, and the shape, size, and color of mushrooms can vary from one fungus species to another.
Fairy ring fungal mycelium growing just below the soil surface in a cross-section of turfgrass. Photo: Tamla Blunt, Colorado State University, Bugwood.org
The bulk of the fungus body is the mycelium. Mycelium is composed of a network of filaments called hyphae that spread through and around their food source as the fungus consumes dead organic matter or infects living organisms. Mushrooms grow out of the mycelium when a fungus is ready to reproduce. The mycelium itself is usually not visible, though it can sometimes be seen on the soil or plant surface during periods of high humidity or wetness.
Removing mushrooms will not remove the entire fungus; it will only hamper the fungus’ ability to spread, because mushrooms contain spores that wind, rain, or wildlife move around the landscape. Mushrooms can usually be ignored when they appear in a lawn. Pluck off mushrooms at risk of being eaten by children or pets by hand or shovel and dispose of them.
Fairy ring mushrooms
Many species of fungi can produce a pattern of mushrooms or turfgrass symptoms called fairy rings. These patterns can be visible year-round, or they can fade or disappear in autumn and winter (during dormancy, or during damp weather when the grass isn’t moisture-stressed) and reappear later. Wet weather promotes fairy ring spread, but hot, dry weather enhances any plant stress symptoms. All types of turfgrass grown in Maryland can be affected by fairy ring fungi, especially when the grass is stressed by environmental conditions like drought or low soil fertility.
Fairy ring mushrooms in a lawn.
Photo: Adobe Stock
Fairy ring mushrooms.
Photo: Adobe Stock
Lawn symptoms due to fairy rings
Fairy ring fungi create rings, arcs, or ribbons of turfgrass that is doing better (greener and more vigorous) or worse (stressed or dead) than the surrounding lawn. The impact the fungus has on the grass classifies the fairy ring as type 1, 2, or 3 (see the table and images below for descriptions and examples).
If two or more fairy rings meet, they generally do not cross each other.
Rings located on a slope tend to be open at the bottom, shaped like an arc rather than a closed circle.
The thatch layer in a fairy ring tends to be pale brown compared to a darker brown of typical thatch.
Mushrooms can appear suddenly along the outline of the ring, typically when adequate moisture is present, or they may not appear for several years.
Fairy Ring Classification
Features and Lawn Impacts
Cause of Symptoms
Type 1
May indirectly kill turf: Can begin as dark green grass, which later dies off during summer dry spells. Often, the ring has three zones within its arc: lush growth on the inner edge, wilted or dead growth in the middle, and slightly lush growth on the outer edge. Mushrooms grow where the center and outer zones meet.
In the outer zone, the fungus breaks down organic matter, and the nutrients made available (mainly nitrogen) fertilize the grass, causing lusher growth. In the inner zone, nitrogen is made available to grass roots as microbes break down dead fungal mycelium. Drought stress is the primary cause of the middle dead zone, as the fungal mycelium repels water and interferes with the soil’s absorption of rain or irrigation water.
Type 2
Turns grass greener: Darker green, more lush turfgrass growth. Generally appear in early spring and last until winter. May turn into Type 1 in hot, dry weather.
Nitrogen release from the breakdown of organic matter enhances grass growth.
Type 3
Neither helpful nor harmful: No visible benefit or damage to the grass. Mushrooms are the only indication of the fungus. Generally appears after rainy weather in lawns that are not frequently mowed.
No prominent symptoms appear, other than occasional mushrooms.
Fairy ring type 1 in a lawn.
Photo: William M. Brown Jr., Bugwood.org
Fairy ring type 2 on a golf course, where the pattern is more irregularly wavy than circular.
Photo: Kevin Mathias, UMD
Fairy ring type 2 on a golf course.
Photo: William M. Brown Jr., Bugwood.org
Fairy ring type 3 in a lawn.
Photo: William M. Brown Jr., Bugwood.org
The diameter of a fairy ring can increase over time, and tends to range from 1 to 20 feet (200 feet is possible in rare cases). Its size and rate of spread depend on environmental factors, such as soil type and weather. Sandy soils and moist conditions support faster spread than drought and clayey soils. The ring’s rate of expansion can range from about 3 to 19 inches per year.
Management of fairy rings
Irrigate and fertilize as needed to alleviate turf stress. While not a cure, this can mask fairy ring symptoms. Always base fertilizer applications on the results of a laboratory soil test performed in the last 2 to 3 years. Lawn care professionals may need to include a wetting agent to help dry soil absorb water.
Improve the absorption of irrigation or rain water by core-aerating the fairy ring area. (Aerate an area that includes 2 feet surrounding both sides of the symptoms). This can help the soil rehydrate if zones of hydrophobic (water-repelling) soil exist due to the presence of fungal mycelium. Do not spread the soil cores on other areas of lawn.
Remove and replace problem areas of turf as a measure of last resort. Thoroughly rototill to disorganize and fragment pieces of mycelium, which may then compete with each other instead of forming a new fairy ring. Or, replace the soil in that area before replanting. Dig 12 inches deep and wide enough to extend at least 2 feet beyond the visible edges of the ring.
Although some fungicides are labeled for the control of fairy ring fungi, in home lawn settings, this is not usually necessary. If warranted, they should be applied by a lawn care professional.
Mushrooms produced by mycorrhizae
The mycelium of some fungi lives on or in plant roots, and both organisms benefit from the partnership. Mycorrhizal fungi in lawns produce mushrooms when they are ready to reproduce. Mycorrhizae are associated with most species of plants, including turfgrass, perennials, shrubs, and trees.
Since these fungi do not cause disease and are making nutrients available to roots, they don’t need to be managed. Mushrooms will disappear from view in periods of dry weather, or if the organic matter content of the soil becomes too low. Over-fertilization and the use of pesticides in a lawn may harm these beneficial fungi, and their loss could make the turfgrass more susceptible to stress, pests, and diseases.
Puffball (Calvatia gigantea) mushroom in a lawn. Photo: Adobe Stock
Fly agaric (Amanita muscaria) in a lawn. Photo: Matthew Beziat, CC BY-NC 4.0
Mushrooms produced by wood decay
Dead wood is decomposed by fungi (among other organisms), and trees or shrubs growing near the lawn may support mushroom growth, even if the rest of the plant is healthy. Buried roots and stumps from trees or shrubs removed months or years ago, or buried lumber or wood chips, can produce mushrooms in lawns where no source of wood is visible. The fungi will subside when their food source has been fully broken down.
Mushrooms growing in a lawn close to a tree, or growing directly out of the trunk or surface roots, might be produced by wood decay fungi that actively infect live trees (as pathogens). Have the tree evaluated by a certified arborist or licensed tree expert. Wood decay cannot be reversed or cured, but the tree might have been able to block its spread internally. Armillaria and Ganoderma are examples of fungal pathogens capable of damaging or killing trees.
Armillaria mushrooms in a lawn. The fungus is growing out of buried tree roots. Photo: Adobe Stock
Stinkhorn mushroom in a lawn, growing on buried dead wood. Immature stinkhorns are egg-shaped. Photo: Adobe Stock
Ganoderma mushrooms growing on a buried tree stump or old root under a lawn. Photo: M. Talabac, HGIC
Mushrooms produced by decomposers and nutrient recyclers
Fungi are important decomposers of organic materials, including turfgrass thatch (dead leaves and roots). The nutrients they release are then available to nearby plants. When environmental conditions are right for the fungus, it produces mushrooms to spread its spores. Some types of lawn mushrooms are ball-shaped instead of the familiar toadstool. No management is needed since these fungi do not infect plants.
Common earthball (Scleroderma citrinum) mushroom Photo: Adobe Stock
Although not true fungi (despite “mold” in their name), these microbes produce reproductive structures that can look like miniature mushrooms, and an aggregation of slime mold might look like a fungal outbreak. They can appear suddenly any time of year, typically during warm, wet weather.
Slime molds vary in color, often white, gray, or pinkish when found in lawns. (Slime molds commonly found on mulch are often yellow or beige.)
Purplish-gray slime mold on turfgrass blades. Photo: Adobe Stock
These widespread organisms feed on other microbes, like fungi and bacteria in the soil and thatch. After several days of dry conditions, the sticky growths will become powdery and fade away.
Slime molds do not infect plants, and disappear fairly quickly. No management is needed, and fungicides will not be effective. Rake or mow dense colonies of slime mold if they are blocking too much light from the grass.
Pinkish slime mold on turfgrass.
Photo: Ask Extension
Slime mold can look like miniature mushrooms.
Photo: Adobe Stock
White slime mold clustered on the tips of turfgrass blades.
Photo: Ask Extension
Drying, withered slime mold on turfgrass blades.
Photo: Rebekah D. Wallace, University of Georgia, Bugwood.org
