Why are there mushrooms in my lawn & what should I do about them?

large fungus in lawn in Amherst
This fungus that was in my lawn is probably in the genus Ganoderma. It was big and tough and difficult to dig out. It fed on what was left underground of a tree stump and roots. When the stump and roots were gone, the mushroom stopped coming back. Photo by Connie Oswald Stofko

by Connie Oswald Stofko

Here’s an email I got recently from a reader:

Hi Connie,

Would you be so kind as to post this question for me?  I thought we were lacking rain so why do I have these HUGE mushrooms growing in my front lawn that gets lots of sun?
 
This is only my 2nd summer in WNY and I am confused!
 
Thanks a bunch o’ coreopsis,
Pam Anderson
Lewiston

Sometimes I ask readers to share tips and opinions on questions from readers, but this question reminded me that my neighbor had asked me awhile back to find out more about the huge fungus growing on our lawns. I decided to ask John Farfaglia, extension educator with Cornell Cooperative Extension in Niagara County, to shed some light on these questions.

Why are these mushrooms growing in my lawn now?

The reason you’ll find these mushrooms in your lawn now is that it’s been dry for a long time and we finally got some rain, Farfaglia said.

Mushrooms need moisture, so we tend to see them in late July or early August after we get some rain. Normally, spring and fall are their most active times because that’s when moisture is available.

The fungi will probably continue to grow into autumn and subside in November when we get colder, freezing temperatures.

“I get them in my yard every year,” he said. “We had a large tree taken down four or five years ago. We had them grind the stump, but there is still some left in the ground.”

And that’s the second thing mushrooms need to grow: food.

Fungi can’t make their own food the way green plants can, Farfaglia explained. Green plants use energy from the sun in a process called photosynthesis to make their own food. Fungi, like animals, must rely on other organisms for food. Fungi feed on old stumps, roots, wood chips– anything decaying in the soil.

If you have mushrooms in your lawn, it’s likely there used to be a tree near that spot. Keep in mind, though, that tree roots can grow 25 feet or more away from the trunk, and you might find mushrooms quite a distance away.

My neighbor and I both had trees taken down, and the fungi developed where the trees had been.

Instead of being mushy and fragile like many mushrooms, these fungi were so hard you couldn’t run over them with a lawnmower without fear of wrecking the blades. They were also difficult to dig out. (They stopped growing after a few years, probably because they had exhausted the wood from the stump.)

Why did our reader find mushrooms growing in a sunny spot?

Some fungi grow in shade, but others can grow in sun. There are thousands and thousands of species of fungi, Farfaglia said.

Some are associated with certain types of trees; some are more common in lawns. There are giant puffballs that grow a foot in diameter and fungi that glow in the dark. And there are portabellas and oyster mushrooms that people commonly eat.

Note: Never eat a mushroom unless you know for sure that it is safe to eat.

Farfaglia took a stab at naming the fungus in my lawn. He thinks it was probably in the genus Ganoderma.

“I admire mycologists (mushroom experts),” Farfaglia said. “Identification and classification of fungi is very complex.”

With some fungi, you have to make spore prints so that you can see the color of the spores in order to identify the fungus, he explained.

“Plant identification is much easier,” he said.

Are those mushrooms in my lawn dangerous?

While many fungi you might get in your lawn are nonpoisonous, some are. That can be a problem if you have children or pets.

Farfaglia rakes his mushrooms up to make sure his dogs don’t eat them.

Since it’s difficult to figure out what fungus you have, just do your best to keep any fungus away from kids and pets.

What should I do about mushrooms in my lawn?

It’s pretty hard to do anything to prevent mushrooms from growing in your lawn; there aren’t any fungicides to deter them, Farfaglia said.

“Any home remedies that you might read about are probably not effective,” he said.

For the hard, leathery kind, you can dig them up. For fragile fungi, you can use a leaf rake to destroy them.

This may scatter spores to some degree, he said, so try to do this when the mushroom is just coming out of the ground, before it is fully mature. When the cap is changing color and starts to deteriorate, it is releasing spores.

If you irrigate your lawn, you may encourage their growth, so you can stop watering your grass.

“Or you can just live with them until conditions change,” Farfaglia said.

When their food source is used up, they will go away.

Mushrooms are fungi that have a fleshy, spore-bearing fruiting body. There are other fungi that don’t look like that, and some of those fungi can cause disease in your lawn. See more about fungal disease and other lawn diseases here.

 

How to get your questions answered

Readers often contact me with questions that I can’t answer. I’m not a gardening expert– I’m a writer by profession. I interview knowledgeable people in order to provide you with great articles on Buffalo-NiagaraGardening.com.

So when someone asks a question I can’t answer, sometimes I post the question and rely on my readers to share their expertise.

Sending a question to me to post can be helpful if you’re looking for a wide range of opinions and don’t mind waiting for the answer. If you want to try this route, email the question to me at connie@buffaloniagaragardening.com and I’ll pose it to my readers in an upcoming issue.

However, don’t send me questions:

  • To find out what is wrong with your plant
  • To identify a particular plant or insect
  • If you need an answer quickly

To find out specific information like that, ask the Master Gardeners with Cornell Cooperative Extension or turn to your local garden center. They can give you the information you need.

6 Comments on “Why are there mushrooms in my lawn & what should I do about them?

  1. I don’t know about those hard wood-like fungi but the softer more fleshy ones will deteriorate with a sprinkling of baking soda.

  2. Since I’ve experienced both kinds, I’ve been told to clean my tools that have touched them so as not to spread the spores. Does this also pertain to lawn mowers? Very interesting article Thank you

  3. Do the mushrooms have to be removed before laying rocks and other ground cover ? They look like they are staying to die but I’m not sure what to do with them

  4. Maricela, do the mushrooms bother you a lot? Are they so big and tough that they get in the way of what you want to do in that space? If so, I would take them out. However, they might keep coming back until they have digested all the tree roots or other plant material in the area. If they don’t really bother you, you can let them be.

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