Q: My lawn was looking fine until the recent rains. Now there are several colors and sizes of mushrooms popping up all over the lawn and in the flowerbeds. Some orange ones are even growing on top of the roots of one of the oak trees. What should be done about these ugly things?
A: Mushrooms are kind of like the flower for a fungus. They are the life-cycle stage where the spores are released to make more fungi. In lawns, fungi usually produce mushrooms when the air and ground are moist because high humidity and wet surfaces are necessary for the spores to germinate and grow.
Fungi in the soil under your lawn and in your flowerbeds are mostly beneficial. They break down dead material into basic chemicals that are used by other organisms, especially plants. The fungi in your lawn are organic matter decaying into nutrients that are beneficial to your lawn grass.
Very often, the fungi in a lawn started where a dead tree was located or where there was another concentration of organic material, such as building materials buried under the grass. Usually the fungus spreads out in all directions from that location. That is why you see lawn mushrooms in arcs and circles. When a couple of circles meet, you might get a figure eight or another shape.
The grass around the circle of mushrooms may be a darker green because of the nutrients being released by the fungi. On the other hand, the fungal growth may prevent water from getting to the grass roots, and the grass may be brown. Either way the situation is temporary, as the fungi will continue moving on under the grass.
If you want to remove the mushrooms, go ahead. They are not harming the lawn but can be unsightly. The fungi in the soil are beneficial and would be very difficult to treat with chemicals. Once the organic material under the grass is consumed, the fungus will die off on its own and not send up new mushrooms when it rains. Fungi and mushrooms are more common in flowerbeds with bark mulch. Decaying mulch will supply the fungi with food for a long time.
There are dozens of species that grow in lawns and flowerbeds, and on tree trunks and stumps. The fungi that decay wood in tree trunks, branches and roots will produce mushrooms at the same time as the soil and mulch-dwelling fungi because the spores need the moist surfaces and high humidity to germinate. Seeing mushrooms on the sides of a living tree is not a good thing. The interior wood of the tree is decaying. Call an arborist to check the health of the tree.
Many, if not most, mushrooms are not poisonous, but many will still cause an upset stomach. I recommend you not only find good identification books for your area but also find local individuals or classes that will teach you more than just a quick identification. For a good starting book, I recommend you get "Edible Wild Mushrooms of North America" by David Fischer and Alan Bessette.
Email questions to Jeff Rugg at [email protected] To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.