Learning how to grow mushrooms is like any skill. Sometimes you succeed. Sometimes you fail. The important thing is to keep trying and learn from your mistakes.
Yet it can be really frustrating to start out with what you believe is a successful mushroom project, only to have it produce nothing. Trust me, I know. It’s happened to me many times!
Although many factors may influence your success, there are some common mistakes that can be easily avoided. I’ve listed eight big ones below, along with practical solutions.
If you’re just learning to grow mushrooms, review this list to save yourself both time and heartache. Even if you’re a veteran, it never hurts to come back to the basics.
For more information on how to grow mushrooms and troubleshooting I’d highly recommend Paul Stamets’ books:
Growing Gourmet and Medicinal Mushrooms
Mycelium Running: How Mushrooms Can Help Save the World
So without further ado, and in no particular order, I present to you……
Reasons Your Mushrooms Are Not Growing
Let’s look at these reasons in more detail:
1. Not Enough Moisture
Mycelium, the underground vegetative growth of a fungus, needs a moist environment to thrive and produce mushrooms. Mushrooms themselves are mainly water, so if you let the mycelium dry out or the humidity level get too low then nothing will happen.
See the picture to the right? I created this outdoor mushroom project with cardboard, straw, and mycelium during one summer. I then patted myself on the back for a job well done, went on vacation, and totally forget about it for a while.
As you can imagine, everything dried out in the hot July temperatures. I was left with hard work wasted, and guilt over baking my poor mycelium.
Solution: Pay attention to moisture and humidity levels! If you grow mushrooms outside, make sure that you keep your bags or bed slightly damp. Make sure to mist or water when you see and feel things drying out.
If you cultivate inside under sterile conditions, you’ll need to monitor moisture and humidity levels more carefully. A cheap hygrometer will help you do this.
2. Too Much Moisture
The opposite of the above problem, and it does happen. Too much moisture can lead to a soggy substrate, mold, and standing water.
Standing water encourages bacterial growth and mold, two things that compete with your mycelium. Although we want to keep our growing media moist, and may even soak it for a day at first, leaving it in standing water is just asking for trouble.
Solution: It’s all about drainage. If you’re using a mushroom growing kit, don’t let it sit in water after you’ve misted it. If you’re using bags or bins or some other indoor method, don’t over-water and make holes in the bottom for water to run out.
Keep this in mind if you’re trying to grow your own mushrooms outside as well. A bed should have adequate drainage, and not be in an area where it will sit in water and encourage mold.
3. Not Sterile Enough
The microbial world is a constant battle of good versus evil. Your mycelium needs to take over and remain in control of your substrate, or it will lose out to mold and other micro-competitors.
Failing to take this into account will lead to bugs, mold spores, and other unhealthy things taking over your project. Even if it does produce mushrooms, you probably won’t want to eat them.
Solution: This is often easier to do when trying to grow mushrooms in outdoor beds. Keep cleanliness in mind by maintaining a good working environment. Follow obvious rules like washing your hands and not working next to the litter box.
Depending on the type of project, you may want to prepare your substrate first to discourage micro-competitors. Pasteurization of straw is one of these methods.
For some indoor projects like growing from spores, you’ll want to maintain strict sterility in order to avoid contamination. Getting equipment such as a flow hood, autoclave, or pressure cooker (right) is often necessary. Do a lot of reading before you do something like this. It’s not for beginners!
4. Not Enough Air Exchange
Mushrooms don’t need as much fresh air as we do, but they still need it. Without any air exchange carbon dioxide levels build up and your mushrooms will emerge as stunted, spindly things that are all stalks and no caps. Very disappointing.
Solution: Make sure your project has a flow of fresh air. Don’t place things in areas with no air exchange.
If you’re growing in a sealed environment, you may want to open it a few times a day for fresh air. Just be aware that when you introduce fresh air you also introduce the possibility of contaminants and lower humidity levels. It’s a delicate dance!
5. The Wrong Environment
The key to learning how to grow mushrooms is to create an environment that’s conducive to the species that you’re cultivating. Make them feel at home!
That means don’t try to grow a warm-temperature mushroom in cold weather. Don’t try to cultivate a wood-loving species on straw. Make sure your mushroom substrate is nutrient-rich. Basically, give the mycelia what it needs to thrive.
Solution: Research. Know what kind of mushroom you’re trying to grow and what they need before you begin. You don’t have to read someone’s PhD thesis, but a little knowledge goes a long way.
6. Bad Spawn
Mushroom spawn that’s old or has traveled a great distance may not be as vigorous and may fail to thrive and produce. It’s no great secret that you should have the healthiest spawn possible to increase your chances of successfully growing mushrooms.
Solution: First off, only buy spawn from a reputable company. If you purchase from someplace sketchy with bad business practices you’ll get an inferior product. Ideally buy from somewhere close to you, so your spawn doesn’t have to go very far.
After that, the best advice is to use it or lose it! Don’t let spawn sit around forever, as it will weaken, create wastes, and possibly contaminate. Keeping it in the refrigerator will extend its life, but it becomes less viable with every passing week.
7. Lack of Research/Understanding of the Mushroom Life Cycle
You don’t have to be a professional mycologist to understand some basic principles of the mushroom life cycle. Knowing how this organism works greatly decreases the chances of your mushrooms not growing. You’ll be better equipped if you understand what mycelium is, how it feeds itself, and what it needs to survive.
Solution: Again, research. You don’t have to know everything, but some research, in the beginning, is important.
Don’t stress yourself and make things overly complicated. Learning to grow mushrooms is fun! Think of it as a fun educational experience, one that’s not restricted by the often-boring boundaries of a classroom.
8. Lack of Patience
Mycelium takes time to grow into a substrate and grow mushrooms. In the case of some mushrooms, like morels, it may even take years!
This is not an activity for the impatient, something I struggle with as a fairly impatient person myself. Yet fear not, careful watching and waiting is greatly rewarded in this hobby.
Solution: Ummm…be patient? Easier said than done, I know!
Enjoy watching things grow and getting into the rhythm of the mushroom life cycle. If it looks like nothing is happening, don’t give up too soon. Wait a little longer and don’t just write the whole thing off.
Often at this stage, I’ve found that all a mushroom project needs are more water and a little more TLC.
I sincerely hope this list hasn’t intimidated you. Rather, it’s just meant to outline some things to keep in mind to increase your chances of success.
Learning how to grow mushrooms needn’t be a complicated or confusing process. Through reading and simple trial and error, I guarantee you’ll eventually succeed.
Every failure is a learning experience. Besides, if you’re learning and having fun, then it’s not really a failure, is it? 😉
Peter B+
my mycelia looked real good in my all-in-one grow bag. I mixed it all up and the entire bag colonized. I opened the top and misted it. Been about 4 days and I am not seeing anything. Noticed this morning that there was a bit of a puddle on the top of my block and to one side of the bag. I tilted the bag to redistribute it up the side. I have the bag in a loosely closed cardboard box and the breather patch or whatever you want to call it is not blocked from an air exchange into the bag above the sub straight. My instinct it to mash up the contents of the bag again so more of the white stuff is near the surface. Please advise.
Jenny
Is this a grow bag that you inoculated or got already with spawn in it? If it’s already inoculated from a company, I would ask them specifically about the product and what to expect from their grow bags.
However, it’s only been four days, so I wouldn’t stress too much. Mycelium needs time and patience. Let it be for a few more days. If you’ve followed the instructions, misting as much as you’re supposed to as well as keeping it in the appropriate location, it should be okay. A lot depends on the type of mushroom which you don’t mention here. They don’t have all the same grow requirements.
Best of luck!
Dan
I have mesculum all over my tub but it’s been right days and still no mushrooms
Jenny
This is not enough information for me to be helpful. If you bought the spores or grow box from a company, I would contact them directly to see what they say. Each mushroom is particular and it varies by who produced it. Good luck!
Gerardo
Hi, I sterilized and inoculated some grains myself. After the bag was completely covered in mycelium I mixed the grain with some sterilized manure and coco coir. It’s been 3 weeks and I have mycelium all over my tub but no fruiting. I have a humidity gage that says the tubs humidity has been at a constant 90%. Any advice on what might be happening.
Jenny
So much depends on the type of mushroom — some take longer to fruit than others. Check with the company you got the spores from to make sure you know the expected fruiting time. Also, air flow and moisture are just as important as humidity. How are those? Again, the appropriate levels depend on the type of mushroom…
john
put it in water, put it in the fridge for at least 12 Hours. Then take it out of the water, let it fall on the floor a few times (in the box of course). then wait for 2 weeks until the first mushrooms start to grow.
Ami
Hi Jenny,
I mixed millet grain with .5% Calcium Carbonate & 2% Calcium Sulphate autoclaving at 121* C at 15 psi for 2 hours. Even after 5 days, unable to see mycelium growth. Used Jau as mother culture (species florida & citrino) in few kgs while others are millet itself. Room temperature 21*.
Moisture content of spawn was perfect. Previous made spawn shows tremendous & best mycelium growth where i had reverse quantity content of CaSo4 (.5%) & CaCo3 (2%)
Looking for solution as I prefer to save my grains 🙂
Thankyou!
Jenny
Honestly, you might just need to give them more time. If you did everything the same as you did for previous inoculations, then it might just be taking more time or be more finicky. It’s super hard to troubleshoot these things without knowing the exact process — maybe some contamination snuck in or some other random thing. While it would be great to save the grains, it might not be possible. There’s always some trial and error and failures along the way. Was it the same culture as before — that can definitely make a difference, meaning they don’t operate on the same exact timelines
mami
Wash and sterilize some leaves of trees that have turned yellow, then cover the bed with it, reduce the amount of ventilation.
mami
The amount of PH bed soil must have between 6/5 to 7/30
TheChemist
Psychodelic Brazilian spores. I opend the bag 2 weeks ago, i have dense even mycelium but no pins? Growing in grow tent with led light, misting twice a day and fanning. No contamination. This is the first mono tub technique in grow tent. Im thinking it is just a way better mycelium growth but i normaly have pins by now. Should i be more patient or need natural light, im not sure. Help
Jenny
I don’t know about growing psilocybe (or what I assume are that) — what the species needs depends highly on WHAT the species is — some want more light, some don’t need much. You need to research the species to know it’s requirements. There are hundreds of psychedelic mushrooms; they don’t all have the same needs. Good luck!
Brandon Lake
I’ve read that more potent spores take longer to fruit. Hope that helps
Kathryn
No fanning?
Jeff
Hi Jenny,
Thanks for the article. The picture of the autoclave, you wouldn’t now by chance who makes it? Looks to be of decent size, kinda what I’m looking for.
Thank You
Jeff
Jenny
I’m sorry, I don’t know the brand. It is a stock photo. Sorry can’t be more help. All the best to your mush growing!
Paul
Hi jenny
I accidentally watered a grow box with mysium in. Bad u thinks.?
Jenny
Well, I guess it depends on how much you watered it… Mushrooms need moisture to develop, but too much isn’t a great thing. It also depends on which species you are growing. IF you’ve added a lot of water, see if you can drain it somehow? It might still be fine if it can drain out well enough.
mami
Distilled water, not just any water
Michael
Growing pink oysters, they spawn lots of Primordia but they flush out and are small coral-like. Placed them in a mon-tub but just more primordia and spindly mushrooms. Gavethemplenty of air but no change.
Jenny
Hmmm, this is tricky. You don’t mention moisture or light. Of course, they need plenty of moisture to grow. Oyster mushrooms also need light to fruit. It could be that you’ve got them in too dark a location? They will spawn in lower light, but in order to produce harvestable fruiting bodies, must have exposure to light.
If this isn’t the issue, then it may be “bad” spawn. It might benefit you to contact the company you got the spawn from and ask them for tips and let them know its not growing properly and see what they say.
Amateur Pretend Scientist
Hi Jenny,
I’m not fruiting either, do you have any advice? Is it possible to have too much air?
-My mycelium looks plump and solid, kind of like cauliflower, but parts of it look more fuzzy.
-I use a filtered aquarium pump on a 15min/hour timer for air-exchange and rarely open my tub.
-The temp has been 72.2 (f), but my target temperature is 70.
-Humidity has been at a near constant 94%
Thanks for any help!!
Jenny
Hi! You don’t mention what you’re growing, which can make a difference. Some species take quite awhile to pin while others (like oysters) are quick. As far as I know, it’s not possible to have too much air. Plump mycelium is good — it does looks quite bizarre right before it pins and fruits. It is possible the substrate is contaminated — is the fuzz blue, green, or black? Everything you’re doing sounds right, so it might just be a matter of patience — double-check the fruiting time of the mushroom species. And,iIf you’ve gotten your substrate from a company, try asking them if they have any tips for their particular species. Good luck!
mami
Reduce the amount of air conditioning, they need a little co2 at first
Pai
Hello!
The substrate we used got very hard and waxy, like a full on shine wax on top and nothing si growing, the other one is slower, but have a few. Can’t find anything online, what could be the issue with this wax development? Thank you!
Jenny
Hi. This is a new one to me. Mycelium might get contaminated which looks like a film of bacteria, sometimes in clumps. But, I’ve never heard of it described as waxy. It could be related to the species you are growing — you don’t mention it here. Also, just had a thought that possibly the substrate isn’t wet enough and that’s why it’s hard? Mushrooms require lots of moisture. Sorry I couldn’t be more helpful. Good luck!
Greg
Hi there, I added coco coir to the top of my colonized mycelia and misted it. I have fruiting around the sides of my monotub but not in the middle. It appears that the coco coir had also been colonized by the mycelia prior to fruiting but the middle has not yet.
Does the coco coir need to be colonized in the middle before any fruiting happens?
Jenny
Hi Greg, you don’t mention which type of mushroom you are growing? That might make a difference. I haven’t used coco coir that much, but I think it should be colonized entirely to fruit. It takes time for full colonization to happen — maybe a couple weeks. So, I’d advise being patient, continue what you’re doing, and see how it develops. Best wishes!
Maggie
Hi! Ive innoculated two spore bags. Its been 3 weeks no mycellium. HELP!
Jenny
Hmmm. Can you share more information — what type of mushroom? What kind of setup do you have? 3 weeks is a long time for many mushrooms, but some do take longer…
cowdough
im having the same issue. i injected p.e. spores into an all in 1 grow bag that came from mushroomsupplies.com for dung loving mushrooms. almost 3 weeks ago and ive still got nothing in the bag. absloutley nothing. since then i ordered some liquid culture. can i inject that in the bag? or would i be wasting it?
Jenny
Hmmm, they can be slow to inoculate (I’d give it more time) but a lot also depends on where you have it. You don’t say anything about the humidity, light, etc that its in. That can affect growth a lot too
David
Hi Jenny,
I am using the monotub method for fruiting. It has been seven days since I transferred the mycelium from the grain spawn jar (brown rice & coffee grounds) to the coco coir substrate mix. The mycelium does not seem to be spreading onto the substrate. I’m wondering if this is due to not adding manure to the substrate. The coco mixture has gypsum and vermiculite. Would it be problematic to open the tub and mix in sterilized manure at this point after the grain spawn and substrate have been mixed for over seven days at this point?
Jenny
What are you growing? I don’t think you need to add manure. It may just be taking its time, spawning can take anywhere up to 21 days for oysters
mami
my frind The amount of PH bed soil must have 6/5 to 7/5 I bet your bed is alkaline