Grow Mushrooms: Learning How to Troubleshoot

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......


Eight Reasons Your Mushrooms Are Not Growing


Infographic on why your mushrooms aren't growing

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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.

Make sure your mushroom substrate is moist enoughSee 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.

Use an autoclave to grow your own mushrooms indoorsSolution: 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 to successfully grow 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

Understand the mushroom life cycle and help your mycelium grow!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: 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 is 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? ;)



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