Worm Bin Mushrooms

After a promising start, our ‘Reader Photos’ section has certainly been quiet. Thankfully, fellow ‘wormhead’ Dwayne C. has helped to get things back on track with this cool photo of mushrooms growing in his worm bin.

It’s not something you see every day, but it is kinda cool when it happens. It has even had me wondering if one could grow edible mushrooms in some sort of worm composting system. I remember reading an article in the print version of Worm Digest (published an number of years ago) describing how the author had put a gourmet mushroom kit in her worm system and ended up being able to harvest mushrooms for several months.

Your chances of seeing actual mushrooms (the fruiting bodies of certain groups of fungi) are much greater in outdoor systems (for obvious reasons) and can be closely linked to the type of material you have in your bin. Manure is an example of a material that commonly is colonized by certain species of mushrooms. Having lots of carbon-rich bedding materials in your bin can also encourage fungal growth.

Last summer I used lots of straw in my outdoor bin and ended up with some big mushrooms in the bin (as shown below).

Generally, the mushrooms don’t last very long (in my experience anyway). I always imagined the worm feasting on the fungal mycelium below, but I’m not really sure if that happens (worms definitely eat fungi – but I’m not sure if they’d actually consume mycelium while it is still alive).

One of the mushrooms that appeared in my outdoor bin last summer.

[tags]mushrooms, worm bin, compost bins, vermicomposting, worm composting, fungi, mycelium[/tags]

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  1. Hi Bentley, interesting inquiry regarding the Mushroom growth. I think I can address the last part since I work with fungi. Essentially the mushroom runs out, rather than being eaten. Like the worms if unfed in a bin would eventually starve, a similar process happens with the mushroom. However, the mycelium strands which are technically vegetative would tend to bind to the soil underneath as the mushroom collapses for lack of nutrition. I can, for instance, grow Oyster mushrooms in a 27 pound bag of newspapers and within 25 days break all the material down to a virtual topsoil. If I kept the supply of papers coming then the Oysters would continue to be like a crop on a farm and could be harvested and even eaten. The topsoil material is then like our compost from Vermi. That said, the mycelium stays in the soils and like a network of strands will help to bind it. Very much as mycelium does in the wild. When we walk on that soft fungal soil, that is what we are walking on. I hope that helps. http://www.fungi.com can also shed some light on this topic. For my part, I do both the Vermi and use Fungal material as well.

    • Chris C
    • May 27, 2010

    This thread is a few years old but I figured I’d add my experience too. I’ve been worm composting for several years now and have a really healthy core family of worms in a tiered worm factory type bin that just tear through anything I throw at them. I recently wanted to ramp up my capacity so I started a new flow through type thing in a large trashcan seeded with a big hunk of worms from my smaller bin. It has been a few months since I started the bigger bin and it seems like they are really starting to get going now.

    Also recently I’ve started getting into mushroom cultivation and am starting to have great success with Oyster mushrooms, pretty much considered to be the easiest mushrooms to grow because they are aggressive and grow on anything. While I was getting the hang of growing the mushrooms I had lots of failures where my mushroom substrate would get badly contaminated with green mold which is pretty common. In those cases I didn’t want to keep the moldy stuff around so I just threw the contaminated substrate in my big worm bin since I was pretty confident the mold would be out-competed by all the other organism. I was right on that front and the mold got it’s ass kicked. The interesting thing is that now my big worm bin is totally teaming with mushroom mycelium. It is really going crazy which makes sense because it’s dark and nice and moist and there’s lots of stuff to eat. I’m still waiting to see how the worms and mycelium get along. Right now it seems like there are very few worms in the areas with lots of mycelium and they are grouped in uncolonized areas. I don’t have any evidence yet that the mycelium is the reason. It’s still a fairly young bin and I’m dealing with other issues that could be causing the worms to prefer certain areas. But I’m confident that If I left things alone for awhile I could trigger some fruiting (by giving the mycelium some light and fresh air). I’m not sure I’m really interested in doing that because I have plenty of oysters fruiting in other containers and I would really like this trash can to be an active worm bin. It would be really cool though if it could all just be symbiotic with the mycelium speeding the composting process.

    I’m not sure this would work very well with any mushrooms other than Oysters since they will really colonize most anything. Most other edibles (like shiitake) are wood lovers and are just much choosier. I guess it’s possible that dung loving mushrooms might be able to be grown in worm poo but I’m not really sure.


    • Chris C
    • June 7, 2010

    Just to respond to my own comment I would warn against anyone trying to combine your worm bin with you mushroom bin. My flow through bin with the worms and oyster mushroom mycelium collapsed so I had to dump it out. It gave me a chance to see what was going on in there. The mushroom mycelium was definitely not cohabitating well with the worms. I only found a handful of worms left and a lot of the bin was solidly colonized with oyster spawn.

    It kind of makes sense when you see it. The mycelium and worms are working towards totally different goals. The worms want everything nice and loose and the mycelium wants to bind everything together into one big network. Not to mention the fact that I think oyster mushrooms have nematicidal properties such that they actually consume nematodes (I’m not positive on that) so it’s possible the mycelium actively went after the worms.

    In short I wouldn’t mix these two hobbies in one bin. Oyster mushroom’s are VERY aggressive so even if you throw spent spawn into your worm bin it will probably take over the whole thing once it gets a crack at the nutrient rich worm poo. Oysters do seem to really like the finished worm poo though so you could definitely grow mushrooms on finished worm compost. Then you would probably have some really great spent compost that you could throw in your garden.

    • Bentley
    • June 7, 2010

    Wow – thanks for sharing all of this Chris! Very interesting. Some people have reported being able to do both successfully, but I don’t think I’d really believe it till I saw it myself. Any time mushrooms have popped up in outdoor worm beds, they’ve disappeared pretty quickly, and generally when there is a lot of fungal growth present in a compost heap/bin there isn’t a big population of composting worms in there as well. I don’t think I’ve seen fungi get the upper hand though – but that does indeed make sense! In some ways reminds me of the struggles I had in systems with plants and worms last summer (different goals – typically one or the other did well, but not both).

  2. Hi! I have a fairly new worm bin (less than a month old). It’s flow through type of tray. I don’t have a lot of worms there yet because I’ve been trying to observe how fast they’ll multiply.

    Anyway, I was surprised this morning to see two big mushrooms growing in the bin! I had no idea if that was a good or a bad sign (that’s what led me to this post). I figured it was moist and dark and that probably encouraged the growth. I wish I had taken pictures though. Later in the afternoon, I checked again and there were three more. Well I wasn’t taking any chances. I cut of the mushroom “heads”.

    If they grow back tomorrow, maybe I can send some pictures and send it here.

    From reading the conversations here though I’m still not sure if mushroom growth is good for the bin or not.

    • Chris C
    • November 1, 2010

    I doubt it’s a problem. Wild mushrooms probably won’t take over a bin like I describe above. Generally I think the worms will keep the bin fungus free once they get going. At least I’ve rarely seen mushrooms spontaneously grow in my bins.

  3. Hi! Today when I checked on my bin, there are even more mushrooms.

    I re-read this post and saw that mushrooms can feed on the newspapers.
    Perhaps it will help if I let them thrive first so they can help with the
    decomposition process. Then when the food is almost consumed, I can cut off
    all their mushroom heads (bwahahah) so the worms can finish the job.

    Does that sound workable? Has anyone tried that yet?

    I also posted a picture of the mushrooms in my blog. Can anyone help me
    identify what those mushrooms are? Thanks!

    • Chris C
    • November 2, 2010

    Identifying mushrooms is a very difficult process. Especially ones that would fall under the umbrella of ‘little brown mushrooms’ because there are a zillion different kinds and they’re not very well described anywhere.

    Like you say they’re most likely aiding in the decomposition process right now. I think you can safely just ignore them and they will die back once they eat whatever they like in the bin.

    Also cutting the heads of the mushrooms won’t really do much. The mushroom mycelium is the actual body of the organism and 99% of that lives underground. The mushrooms themselves are just the fruit like apples on an apple tree.

  4. I agree with Chris – there are LOADS of little mushrooms that look like that.

    I suspect that you will see the mushrooms vanish pretty quickly without any decapitation necessary!

  5. I’ve done a little research on it too. It seems mushrooms do help with the decomposition process. That said, yes, I’ve stopped decapitating them. In fact, I took one of the mushrooms including the growing medium (in this case, newspaper) and moved it to another bin. I’m hoping that bin will also get loads of mushrooms to help the worms in the decomposition process.

    What I don’t like though is that touching or breaking the mushroom “head” stains you with black ink. It’s discoloring my worm bin. Tsk.

    • Daniel Herrington
    • November 3, 2010

    Yes it does, it works well with the worms. I conductected experiments with Western University in Canada to this extent. We followed the blueprint of a Mycobiologist named Paul Stamet. You can see his vids on http://www.TED.org. He also has books published that touch on this. But essentially to give an idea. We digested 27 pounds of newspaper in 30 days using Shitake and Oyster mushrooms. Naturally it was a controlled experiment.

    Collectively the process is 18% faster but is only good in the summer months. once the mycelium from the spores spread they will actually break down the vegetable oil and hydrocarbons in paper faster than the worms.

    However, out attempts to get the government to recognize this advantage fell on deaf ears. So I do it for my own recreation with various universities interested in Fungi.

    Hope that helps.

    • Chris C
    • November 3, 2010

    Mushrooms definitely are great decomposers. I’ve had great luck using them with worms (just not simultaneously since they compete). For instance I filled a big old trunk from the thrift store with coffee grounds (lots of coffee grounds) and mixed in oyster mushroom spawn. For the next few months I harvested probably 20lbs of oyster mushrooms from it. Then once the oysters ran out of steam I dumped a bunch of worms in there. Now they’re loving it. And it’s the lightest fluffiest soil I’ve ever seen (it’s definitely not coffee grounds anymore).

    Certain species of oyster are tolerant to low temps (at least as low as we get here in CA). I’ve got some pleurotus columbinus (blue oyster) growing out on spawn and I plan to grow it during the winter. However neither oyster nor shiitake are wild about cardboard in my experience. Reishi mushrooms on the other hand go crazy for the stuff. Overall mushrooms + worms can break down a ton of organic waste.

  6. In a lot of materials I read for commercial worm cultivation, they suggest anaerobic decomposition of about two weeks before using the material as feedstock. I am wondering if it would be more efficient to introduce mushrooms instead as a pre-composting method.

    • Chris C
    • November 4, 2010

    I’m not really sure. I’ve never really gone for ultimate efficiency with my worms. They seem to do pretty well with my attitude of benign neglect.

    But like I said above I think worms and mushrooms make a great team for breaking down volume materials. Aside from the efficiency there is a huge upside in that you could produce a bunch of food before sending the remaining substrate to the worms. Growing mushrooms takes some labor but I could see it easily being incorporated into a worm business.

    For instance if one lived in an urban/suburban area with lots of coffee shops you could hit all of them for free coffee grounds, grow a ton of mushrooms off them for eating/selling and then take the spent substrate and feed it to the worms. The mushrooms break down the grounds somewhat and probably mellow out the PH for the worms.

    Neither worms nor mushrooms are a business for me and I don’t quite have the room to go large scale with it. But I do like making good use of others’ waste.

    • Kenny Rupert
    • February 3, 2011

    This goes out to Daniel Herrington. If you get this I would love to hear/read any info you have on your experiments. I’ve read all of Stamets works and know a decent amount on the subject, but always trying to learn more, especially if it pertains to vermiculture as well. I can be reached at my first then last name(no space) at hotmail. Thanks.

    • Daniel Herrington
    • February 3, 2011

    Bentley, I have sent you and email with opinions and data on what was done during the experiments. I trust you are still at the email address I have for you when you first began. If not. Please email me back and I will resend my data. You may wish to edit it if you want to post it as it is rather long.

    • Daniel Herrington
    • February 3, 2011

    My apologies, I received the email in my Inbox and thought it was from Bentley. I have not way of forwarding my message to you. I have asked Bentley too and hopefully he is checking his email and will do so.

    Again sorry for the confusion. I only hope Bentley gets it to you quickly which I am sure he will. To write it here would be a long long message.

    • James Astor
    • April 1, 2011

    After reading the comments on this article, the concepts described above are very interesting. Daniel, I too would love to see/talk more about your experiments. I’d love to hear from you, my e-mail is: astor (dot) james (at) gmail (dot) com

    • Adam
    • July 8, 2012

    I left a picture on your FB page of what I believe is mycelium growing on the plastic in one of my worm bins. There was even a worm actively eating it. I’ve seen pictures of ants having mushrooms sprout from their heads after eating it. Is this something I should worry about?



    • Adam
    • July 8, 2012


    This is where I saw the ants if you’re interested. I’m just going to leave the mycelium to see if it turns into a problem.

    • Adam
    • July 8, 2012

    I believe my picture shows that they eat mycelium while still alive.

    • Kenny
    • July 8, 2012

    It is very unlikely that the mycelium growing is from a cordycep(fungi that pops out of an insect’s head). From all small experiments I’ve done, I’ve seen nothing bad happens to the worms who eat mycelium.

    • Bentley
    • July 8, 2012

    LoL – you don’t have to worry about fungi (or anything like that) attacking your worms and turning them into mushroom food. That particular variety attacking the ants is pretty specific to its target organism. Virtually all the time, it’s the fungi that should be worried (haha), since the worms do love munching on them!

    • Bentley
    • July 8, 2012

    Sorry Kenny – replied before I saw your comment (was being held for moderation).
    BTW – as I mentioned in response to the Facebook posting, I actually think it might be a slime mold in Adam’s bin. These are very common in composting systems, and have a somewhat different appearance than fungi. They often branch out in a tree-like manner and aren’t fluffy/hairy the way fungal mycelium is.

    • Adam
    • July 8, 2012

    I don’t know. I’ve googled images for mycelium and some of the pictures look identical to mine. Interlocking highway system of “roads” is what it looks like. I haven’t seen any slime mold looking like what I have, but you never know. They both have similar properties.

  7. I am still reading all your stuff…hang in there. This is a very valuable site.

  8. You want to talk about fungus, the best source if at this link.


    Covers everything from mycology to shitake mushrooms. it is the foremost information from Paul Stamets

    • Cheri
    • July 19, 2012


    Hopefully the photo posts. I am new to vermicomposting and i discovered this in my bin this am. How do spores get intoduced to the bin when no garden or yard waste is put into this bin.

    • Uma
    • October 29, 2012

    This question is to Chris. I am sorry, I am new to this thread, and hence am 2 years late. You say that you first compost coffee grounds with mushrooms and then use worms to compost them further. Can you reverse the process? In other words, I have lots of vermicompost, free of worms, but have not had any luck growing mushrooms in the worm-free compost. Any suggestions? Thanks,

    • kenny
    • October 31, 2012

    I would assume the vermicompost would be bacteria riden. It would be quite difficult to get a fungus to take with all that competition. If you sterilized or pasteurized it would be possible but it depends on what your medium is. Only Phoenix oysters and similar oysters seem to like the coffee grounds.

    • Kairin
    • July 9, 2019

    My worm bin population collapsed due to neglect. Currently slowly getting my worm bin to repopulate.

    What I’m also planning on doing is getting oyster mushroom to grow on worm compost in a separate container.

    As in, I’m thinking of setting up 3 bins.

    1.) one bin will be 100% worms and vermicomposting
    2.) one bin will be 100% just oyster mushrooms mycelium and substrate
    3.) one bin will a mix of oyster mushroom mycelium and substrate and about 50% of excess worm poop added in.

    would anyone know if the oyster mushroom mix with worm poop will proliferate and have robust oyster mushroom growth?

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