During August, the Augusta area received more than 10 inches of rain. According to The Augusta Chronicle, this August has been the wettest in 70 years, beating the August 1967 total of 8 inches. The wet weather has led to an increase in mushrooms. The Cooperative Extension office has received many queries this month about mushrooms and how to eliminate them.
Mushrooms are above-ground fruiting bodies of fungi that live in the soil. Sid Mullis, County Extension Agent for Richmond County, explained it best when he called mushrooms “the flower of the fungus.” They usually emerge when rain follows extended dry periods. Dry weather stresses the fungi. When water becomes available it triggers the reproductive mechanism and we get mushrooms.
These fungi feed on decaying organic matter, such as old roots, stumps and thatch. When these fungi are present in your soil or mulched areas, mushrooms will seem to pop up overnight after a rain. While they may be unsightly, many of these fungi are completely harmless to the landscape. Mushrooms may be removed by hand-picking, but this does not remove the underlying fungus in the soil. Mushrooms will return when conditions are favorable.
An interesting specimen brought to the County Extension office this month was a type of Bolete. This specimen was an 8-inch white mushroom with pores on the underside of the cap. The pores are a unique identifier for this type of mushroom. Boletes form an intimate relationship with the roots of trees and other plants called a mycorrhizal association. It is a symbiotic relationship between the fungus and the plant’s roots that extends the plant’s reach to water and nutrients.
As the fungus invades the roots of a tree or other plant roots, absorptive property of the fungus extracts minerals from the soil and brings them into the host plant. In return, the fungus obtains vitamins and other organic materials from the tree. If the mushrooms are unsightly, they may be removed by hand-picking.
One of the most eye-catching and descriptively-named fungi is a type of slime mold commonly referred to as “dog vomit.” Fuligo septica, the scientific name, typically occurs on mulch. It begins only a few inches across, but rapidly expands to several feet in diameter. Colors vary from bright yellow or orange and fade to brown or tan as it dries. Slime molds do not harm plants and dry up in a few days. If their appearance is offensive, they can be scooped up and thrown away.
Another interesting fungus family is the Phallaceae, which includes the mushrooms known as stinkhorns. While the smell or appearance of this mushroom may be undesirable, they are beneficial to the landscape. This fungus is a decomposer and it is considered beneficial because it helps break down decaying plant material. Stinkhorns do not harm plants or grasses. If the smell is unbearable, remove the mushroom and place it into a sealable plastic container.
It is a misconception that mushrooms are a sign of soil problems. Many fungi are a vital part of a healthy soil that decomposes dead plants and other organic matter. There are some fungi that can harm the landscape. Fungi would need to be identified to determine if it would be detrimental to the lawn. Because mushrooms are the fruiting bodies of fungi, removing them doesn’t kill the underground fungi. The main reasons for removing mushrooms are to remove the risk for children and pets and to improve a lawn’s appearance.
Never eat an unidentified mushroom. Some mushrooms are poisonous to humans and animals. To remove mushrooms in the landscape, pull them up or run them over with the lawn mower. The mushrooms, however, may reappear when conditions are favorable.