Are Mushrooms In Your Raised Bed Soil A Cause For Concern?

If mushrooms are growing in your raised bed, or popping up all over your garden, then you might be worrying something is wrong. But don’t worry! In most cases, mushrooms are surprisingly good for our garden and they will provide countless benefits to your plants.

You may have questions like, “where do mushrooms come from? Why are mushrooms sprouting in my yard? Are they harmful or helpful? How can I get rid of them, and should I?”

Millions upon millions of beneficial fungi grow under the soil, and the mushrooms are the parts that pop up above the ground. While it’s a strict no-no to eat them, you have the option to either let them be, and they’ll soon retreat back into the soil, or you can uproot the mushrooms or simply blend them back into the soil.

If their appearance displeases you or if you harbor concerns about certain toxic varieties, then mushrooms could indeed pose a problem.

Yes, some mushrooms are toxic to humans and can be harmful to dogs and cats, hence it’s advisable to remove them from garden beds with edible crops to prevent contamination.

Keeping reading to learn more about the fascinating world of mushrooms and how they will make your garden a better, healthier place and what you can do and what not to do about them in the long run.

Where Do Mushrooms Really Come From?

ushrooms after rain

When we think of fungi in the garden, we often think of something bad that is making our plants mold or rot. Underneath our feet, however, good fungi are growing to create healthy soil.

Countless microscopic filaments (hyphae) join together to create masses of fungal networks called mycelium. These fungi can be invisible to the eye, or they can develop into threads of root-like structures in the soil, and a single spoonful of soil can contain miles and miles of these fungal threads.

When the conditions are right, the mycelium form together above ground to create mushrooms, which are actually the reproductive structures (sometimes called fruiting structures) of a fungus. Mushrooms produce and release spores, which will in turn create new hyphae and form a new fungus.

There are roughly 11,000 named mushroom species in North America alone, and scientists agree that this is but a small part of the actual different fungi out there.

Why Are There So Many Mushrooms Growing in My Yard and Garden?

If you have mushrooms growing in your garden soil, it is because the conditions are just right for these fungi to grow and spread. While each mushroom is unique and thrives in different environments, most mushrooms grow best with the following:

  • Growing Medium: Mushrooms need something to grow in, and this is usually decaying organic matter, especially wood chips or decomposing wood, straw, leaves, manure, unfinished compost, and more.
  • Temperature: Mushrooms “bloom” in different temperatures depending on the species, but most fungi prefer air temperatures around 15C(60F) and the soil temperature can vary between 7C and 24C (45-75F).
  • Humidity: Mushrooms like things moist, and they like when the relative humidity is around 80% to 90%, which is why they often show up after a rainy season or when you have just watered your garden.
  • Soil pH: Most mushrooms grow best when the soil is slightly acidic, though they will grow in a wide range of soil acidity. In fact, soil pH makes almost no difference to the viability of a fungus or the production of mushrooms.
  • Shade: Mushrooms do not photosynthesis like plants do so they need very little light, which is why you often find mushrooms growing in the dappled light of the forest floor. In the garden, mushrooms often grow near the shaded edges of beds, or underneath the protection of a plant’s foliage.

In most cases, the conditions in which mushrooms thrive are good for your garden and mushrooms are a sign of healthy soil with good moisture retention and lots of organic matter. So, if mushrooms are appearing then you probably have a good environment for growing plants.

Are Mushrooms In Your Garden Soil A Good Or Bad Sign?

Mushrooms are also extremely good for your soil and your plants. Mushrooms will benefit your garden or raised bed by:

Are Mushrooms In Your Garden Soil A Good Or Bad Sign?
  • Improving Plant’s Root System: Many fungi will attach themselves to the plant’s roots, reaching far into the soil and improving the root’s surface area a thousand-fold.
  • Improving Soil Structure: Fungi produce organic compounds that loosen and aerate the soil while holding the soil together at the same time.
  • Disease Resistance: Fungal activity amongst the roots makes healthier plants that are more resistant to disease.
  • Drought Tolerance: Healthy fungi in the soil also improve the plant’s ability to handle drought.
  • Adding Nutrients: As mushrooms consume undecomposed organic matter, they release nutrients into the soil which become available to the plants.

You can read this article here from the University of Oregon for more information on how vital good fungi (and mushrooms) are for your garden.

Can You Eat Mushrooms From Your Garden Beds?

Can You Eat Mushrooms From Your Garden Beds?

A good rule is you should only eat mushrooms that you have planted yourself unless you are experienced enough at foraging to correctly identify the edible species.

Of the 11,000 identified mushrooms only around 3% of them are poisonous. Most of the poisonous ones will only cause gastrointestinal issues, hallucinations, or other issues. However, of the 250 to 300 poisonous mushrooms in North America, approximately70 to 80 species are fatal if ingested.

So, while the chances of you getting a poisonous one is low, eating the wrong mushroom might be the last thing you do.

What To Do With Mushrooms In Your Raised Beds

Once you see mushrooms popping up in your garden, the fungi are already well-established in the soil. Here are some ways to manage mushrooms in your garden:

Leave Them Alone

Leave Them Alone

You can leave mushrooms alone and they won’t cause any problems. In most cases, the mushrooms will disappear and stop growing on their own once conditions become less favorable, such as when the weather changes or the soil dries out, or all the organic matter has been fully decomposed or exhausted.

Once the mushroom’s purpose is done (i.e. it has delivered its spores), it will disappear and probably won’t return until next year.

However, one thing I’ve noticed is that when I let them stay and they produce spores, I tend to see even more mushrooms the subsequent year. But honestly, seeing mushrooms pop up doesn’t really bother me. In fact, I find their presence rather fascinating.

Removing Mushrooms

Removing Mushrooms

There are some reasons you might want to remove mushrooms from your soil. For starters, mushrooms will release their spores and you might not want fungi spread around your garden. You might also be worried about children, pets, or even adults accidentally ingesting a potentially poisonous mushroom.

Remember, even if you get rid of any mushrooms that sprout, the fungi will still be in the soil and new mushrooms will come back year after year (and maybe even again in the same season).

Here are some easy ways to deal with mushrooms:

  • Pull: Pluck any mushrooms that sprout and toss them in the compost bin. Bear in mind that you might have these fungi growing in your compost if the heat doesn’t kill it but its presence will be very beneficial to the decomposition process. Make sure to wear gloves when handling mushrooms in case you are dealing with a poisonous species.
  • Incorporate: The easiest way to deal with mushrooms is to simply turn them into the soil with a shovel, rake, or even your hand (gloves are recommended). The mushroom structure will quickly break down and benefit the soil. 
  • Make The Garden Inhospitable: Mushrooms are very sensitive to their growing environment and are thus very easy to eliminate by changing the conditions of your garden. Here’s how you can eliminate existing mushrooms and prevent them from appearing initially: lessen the watering frequency, let the soil dry out, enhance drainage, aerate the soil, employ well-decomposed compost, and ensure more sunlight reaches the area.
  • Vinegar: The acid in vinegar will quickly kill any mushroom it comes in contact with. Mix approximately 1 part vinegar with 4 parts water and spray or pour it directly on the mushroom. Make sure to only apply it to the mushrooms as vinegar can kill any plant or foliage it comes in contact with.

Remember, this is only a reasonable solution to deal with mushrooms that have formed. Dumping lots of vinegar on the ground is NOT an effective way to remove underground mycelium because this quantity of acid would kill all living things in the soil and make the ground inhospitable to your plants.

What You Shouldn’t Do To Mushrooms

Whether you want mushrooms growing in your garden or not, here are a few things you should never do to rectify the problem:

  • Conventional Fungicides: Chemically based fungicides should not be used in the garden. In the first place, they are very ineffective when dealing with mycelium so even if you eliminate the mushrooms, more will grow. Secondly, they do far more damage than good, as they indiscriminately kill both good and bad fungi in the environment.
  • Sulfur And Lime: Sulfur and lime are common soil amendments to adjust the pH of your soil. The theory is that adjusting the acidity or alkalinity to a level that is inhospitable to mushrooms will eliminate the problem. As we have seen, however, mushrooms grow in a wide range of pH so this is not a very effective method. Furthermore, if you can adjust the pH to a point where mushrooms won’t like it then chances are your plants won’t either.

Mushrooms: A Sign of Healthy Soil

When I was young, I was taught that if you even touch a wild mushroom, let alone eat it, you could die. While I understand this drastic exaggeration was used to keep children from eating psychedelic ‘shrooms in the lawn, introducing this fear of mushrooms severely limits a person’s appreciation for these vital and fascinating parts of nature.

While I also teach my children not to eat mushrooms, I hope we can all stop viewing them as a “problem” and encourage them to grow and thrive in our soil and gardens.

Mushrooms In Garden FAQ

If you find mushrooms growing in your raised beds, here are some quick answers to any questions you might have:

Q: Can You Eat Mushrooms Growing In Your Raised Beds?

A: While many wild mushrooms are edible, some of them are poisonous. Do not eat any mushrooms unless you can tell for certain they won’t kill you!

Q: Will Mushrooms Hurt Your Plants?

A: No, most mushrooms will benefit your plants and soil and will not harm your garden in any way.

Q: Are Mushrooms Bad For Your Garden?

A: Not only are mushrooms a sign of healthy soil full of organic matter, but they also provide numerous benefits for the soil and plants.

Q: Can You Put Mushrooms In Your Compost?

A: Yes, mushrooms are very good for your compost pile and can help with the decomposition process.

Q: Do I Have To Remove Mushrooms From My Raised Bed?

A: While you can get rid of any mushrooms that grow in your garden or raised bed, you can also leave them alone and they will most likely disappear after they have produced their spores.

Q: Should I Use Fungicides On Mushrooms?

A: No. Not only are fungicides relatively ineffective in dealing with mushrooms and the underground mycelium, they are bad for the environment and will kill far more good things that bad.

Amber Noyes

Written By

Amber Noyes

Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.