The Homeowners Column

The Homeowners Column

A Fungus Amongus

Photo of Sandra Mason

Sandra Mason
State Master Gardener Coordinator
slmason@illinois.edu

As you wander your yard you may notice a fungus amongus. After a rain a flush of mushrooms may have appeared overnight in the wood mulch near you. Now before you get concerned that you're living the invasion of the body snatchers, realize most of these are growing on decomposing plant material. Organic mulch, such as wood chips or shredded leaves, is naturally in the process of decomposing. That's just what stuff that "once was alive" does. Like a teenager with a cell phone, they just go together.

Now let's drop down to the life of a fungus. When we see a mushroom or toadstool we are seeing the fruiting or reproductive structure of the actual fungus. Just like an apple on a tree, the mushroom contains the spores or fungus "seeds" to produce more fungus. We do not see the majority of the actual fungus as it happily lives underground. They are either living off the mulch itself or in the case of slime molds are living off the bacteria and other critters in the mulch. They may also be growing off of old tree roots. The tree may have been cut down years ago, but the roots are still decomposing. Fungus can live in the soil for years and only produce mushrooms when the environmental conditions are right.

You may see what we typically call mushrooms. The fruiting structure can also look quite weird. Ones that you may see are stinkhorns, puffballs or slime molds. Stinkhorns are guaranteed to illicit a giggle. Their reproductive structure looks like a giant slimy finger or a male reproductive structure. The spores are on top in stinky goo. The goo attracts flies which help to spread the fungal spores.

Puff balls look like the name implies - a round ball. Some can get as large as basketballs and can be as white as fresh snow. As they ripen the ball darkens and develops a hole in the top. When the structure is disturbed it sends out a puff of spores. These smokestacks are irresistible play toys.

Slime molds are (to use the technical terminology) just icky. They are not true fungus and will often appear on the top of mulch. It looks like your dog got sick, hence its other name "dog vomit fungus". Some may be bright yellow, but can also be white, gray, brown or red. They quickly turn brown and powdery until they are gone in a week.

Ok, what's the bottom line on this landscape fungus? There are certainly some fungus that cause plant disease, but it's usually not these guys. Generally these are not harmful to landscape plants or people and pets unless they are eaten. Some mushrooms are edible and some poisonous. Even guidebooks do not give you the necessary details to safely eat mushrooms. Question is "Do you feel lucky kid?" If you want to eat mushrooms, go out hunting with an old mushroom hunter. If they have made it past fifty years old with their liver intact, then they are probably doing it right.

So what can you do? Wait and the mushrooms will dry up. However you will probably continue to see the mushrooms periodically when conditions are right often after a heavy rain. Eventually the food source will be depleted. If you have small children or pets, you should rake or mow off the mushrooms as they appear. Just aerating the mulch will often help. With slime molds a heavy stream of water will disperse the mat. When you cut down a tree, try to remove as much of the stump and roots as possible. Decomposing fungus may be a nuisance, but are important in the nutrient cycle as they release plant nutrients back into the soil. Plus they are great conversation starters.

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