August 14, 2010

1 - Mushrooms are a necessary part of the landscape environment.

Yard and Garden - August 14, 2010


I have mushrooms growing all over my lawn. Should I worry about them? How can I get rid of them?

- Susie K.



I have received this question from several other parts of New Mexico recently. One person was extremely concerned because one of the mushrooms in her lawn was one known as the "stink horn" mushroom. In addition to the unpleasant smell, it has a rather vulgar appearance and she did not want it in her lawn. Other callers are concerned that their pets will eat them, and some are concerned that the mushrooms are dangerous for their lawns and gardens.

The fact is that the mushrooms (or toadstools) are the fruiting structures that produce spores to reproduce a fungus that has been growing out of sight for a long time. When weather conditions are proper, the mushroom is formed to spread the spores and create new fungi. Those mushrooms most common in New Mexico are probably not toxic to pets, but unless you can positively identify them, do not eat them yourself and discourage your pets from eating them. Most pets may investigate them, but probably will not eat them.

Frequent irrigation, and especially the monsoon rains, creates the proper environment for the appearance of the mushrooms. The fungi that produce the mushroom have been decomposing old tree roots, lawn thatch, and other dead organic matter in the landscape. In other words, they are creating compost and releasing nutrients from this organic matter to the living plants in the landscape. They are beneficial.

Getting rid of mushrooms is impossible. One person thought they had arrived in his landscape on grass seeds. That is not the likely source. Mushroom fungi may come with manure or compost that is applied to the landscape, but the most common source is the wind. Mushroom spores are very small and travel great distances in the winds and breezes. As you read this you are probably inhaling mushroom spores, unless you are in an electronics "clean room" or hospital operating room. Most people will suffer no ill effects from air-borne spores. Some people will exhibit allergies as a result, but this is unavoidable except for people who must live in bubbles with filtered air.

Managing thatch in the lawn and irrigation are ways to minimize the growth of fungi and reduce the number of mushrooms formed, but they cannot be eliminated. If they could be eliminated, they should not be eliminated because they serve a valuable function in our environment. Mushrooms can be interesting to observe (except those with a vulgar appearance or foul smell). So, enjoy the natural process of nutrient recycling in your landscape when you see mushrooms.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email:, office: 505-865-7340, ext. 113.


For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms.

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