Mushrooms are the visible fruiting structure of some types of fungi. They come in many shapes and sizes, but their purpose is to house and distribute the spores of the mushroom. Most fungi are beneficial. They help to decompose plant material, thus releasing nutrients and making them available for plant growth.
Mushrooms produce spores that are borne on the wind until they reach a favorable place to grow. They then settle in, sending out fine filaments called hyphae. Hyphae perform different functions in the garden. Some decompose organic matter; others are symbiotic; and still others are parasitic and cause disease.
When enough hyphae grow together, they form a group called a mycelium. These mycelia can develop in the soil for years and only form the fruiting heads, or mushrooms, when conditions are favorable—after prolonged wet weather, for example.
Many mushrooms seem to appear overnight and grow exponentially. I firmly believe that those clumps in my yard are growing as I watch. In reality, it takes a few days for the fruiting bodies to form. They expand quickly by absorbing moisture. This rapid growth is the source of some common phrases, such as “to mushroom” or “to pop up like a mushroom.”
Mushrooms do not live long. The ones in my garden flourish for about two weeks then turn into a mushy black pile. Mycelia, on the other hand, can live for years. There is a mycelium structure of an Armillariasolidipes in the Malheur National Forest in Oregon that is estimated to be more than 2,400 years old.
Mushrooms have been used for many purposes over the centuries. We are all aware of the yummy edible varieties in the grocery store. Throughout history, mushrooms have been thought to have medicinal value, and they are still used in traditional Chinese medicine. Since the 1960s,American researchers have studied the possible medical benefits of mushroom extracts.
Unless you are well acquainted with the different species, do not eat wild mushrooms or other fungal fruiting bodies. Many species are poisonous and hard to distinguish from edible varieties. Keep small children and pets away from areas of your yard where you have seen mushrooms growing. Remove all mushrooms from the area before allowing a child or a pet to play there.
How do you remove these grotesque garden additions once and for all? I say “grotesque” because they give me the shivers. Pulling off the visible mushroom doesn't do much other than maybe stop that particular crop of spores from spreading. The mycelia are still underground, waiting for the next session of wet weather to send up more mushrooms to release more spores. For more information on poisonous mushrooms in California, visit the Bay Area Mycological Society web site (www.bayareamushrooms.org).
Workshop: Napa County Master Gardeners will conduct a workshop on “Rose Pruning and Maintenance” on Saturday, January 17, from 10 a.m. to 2 p.m., at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. This workshop will feature demonstrations on rose bushes to show and explain proper pruning techniques. Master Gardeners will discuss various types of roses, common rose diseases and routine maintenance including watering and fertilizing. Online registration (credit card only) Mail-in registration (cash or check only).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners ( http://ucanr.org/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.