Unidentified Fungi in the Garden

by Jim
(Missouri, USA)

I've been seeing a large amount of fungi in the community garden I manage. I haven't identified them. I don't even know if they're toadstools or mushrooms.

Is it a good idea to rake them up and toss them into my compost bin? If they're poisonous I fear the compost would then be unsuitable for growing fruits and vegetables.

I live in St. Louis, MO. Annual average rainfall is 36 inches. Half of a year's rain fell between March and June last year.

By the way, ~ fantastic website!

The Compost Gardener Answer

Jim, thanks for your question.

Fungi are a fantastic thing to have in the garden. They do a great job of decomposing the more carbon rich material like wood chips, leaves and straw in your garden and as they do this the nutrients in those materials become available to the plants.

Put Them in the Compost

If you are worried that someone might decide to eat them raking them up and putting them in the compost would be a good solution. It won't make the compost unsafe for use on the garden and will supplement the fungi already at work in the compost pile.

Fruit of the Mat

The mushroom or toadstool you are seeing in your garden is the tip of the iceberg of the actual fungi. The picture above is from my garden where a bunch of little mushrooms sprout up each year. They are the fruiting body of a much larger mycelium mat, an intricate web of filaments the fungi send out. A single fruit or mushroom is being supported by a large area of mycelium - for example the very yummy chantrelle mushroom would have a mat of about 70 square meters or yards supporting it.

Don't worry though, most fungi are very good for the garden and some are essential. I have several pages on this site about mycorrhizal fungi you might enjoy. The mushrooms in your garden are likely a type of mycorrhizal fungi associated with a nearby stand of trees.

Mushrooms or Toadstools - Don't Eat Them Unless You are a Mushroom Expert

I used to think there were two types of fungi - mushrooms being the good edible and safe ones and toadstools being poisonous and generally evil.

I was wrong. It's estimated that there are around 1.5 million types of fungi. Of these only about 75,000 have been identified and of those only about 200 are really edible. At least another 200 are poisonous enough to either kill you or make you wish you were dead. Some of these look very similar to each other.

Unidentified fungi in compost
by: Margaret

We have had so much rain here in Louisiana lately that I can't keep up with keeping my compost aerated. It smells to high heavens. This morning it had little white mushroom type growths all over it - very tiny but all over it. I am concerned about putting it on my garden to grow vegetables. Is there any time where compost gets dangerous to use?

Margaret...
by: Leslie

Hi Margaret,
Those little mushrooms should not be a problem. But... the fact your compost stinks to high heaven is an issue. It's too wet and has no air in it... but you already know that.

I had a similar problem last summer after a series of unfortunate compost additions and a big rain dump. What I'd suggest is once the weather gets dry enough dump out your compost and add dry coarse material. This will let your compost breathe without a bunch of energy on your part.

Then give your compost a time to cure. You will know it's safe to use by the smell. When you use it put it on top of the soil rather than digging it in. All will be well.

Thank you for the Question and Info!
by: Debbie Rhode

Thank you so much, I was wondering the exact same thing--there is fungi in my compost and I did not know if it was safe, or if I needed to toss it and start all over again. I appreciate this blog, thank you! And thank you Jim, for asking. I live in Central Washington, and typically we don't get much rain, but this year has been exceptionally rainy. My compost is right next to our cherry orchard, too!