Growing Mushrooms in a Greenhouse - Complete Beginners Guide (2024)

Growing mushrooms at home can be challenging – especially for people who live in unstable weather conditions or environments that are too cold to successfully grow mushrooms.

The good news is you don’t have to move your entire life just to pursue your fungi growing dreams. Growing mushrooms in a greenhouse is a great alternative, and one that many around the world have turned to, to cultivate delicious gourmet mushroom farm in their own backyard.

Today at the Garden Bench Top, we are going to explore the tools and equipment you will need to successfully build a greenhouse mushroom grow set up.

We will also weigh up the pros and cons of using an indoor mushroom greenhouse, when compared to using traditional forms of mushroom growing techniques.

Finally, we will also provide you with some useful tips for growing greenhouse mushrooms. Particularly for those seasoned mushroom growers, who are pondering the question ‘Can you Grow Mushrooms in a Greenhouse?‘.

So dust off your garden gloves, strap on your sun hat and let’s get into growing a mushroom garden.

Step-by-step Beginners Guide to Growing Mushrooms in a Greenhouse

In this section we are going to guide you through the general process of setting up your very own mushroom farm in your greenhouse.

You will find a list of the recommended raw materials that you need for every mushroom kit. As well as some additional tools and pieces of equipment that we highly recommend specific to growing mushrooms in a greenhouse.

Things you will need:

• Mushrooms spores (of choice) – if you are unsure which type of mushroom you should grow, check out our mushroom guides HERE.
• Growing Medium/substrate (of choice)
• Sterilizing Alcohol
• Hygrometer (humidity Checker)
• Thermometer (temperature checker)

Steps to Building a DIY mushroom greenhouse kit

1. Step 1: Establish an area in your greenhouse. From the very beginning, you will need to figure out a space or area in your greenhouse that will belong to the mushrooms. As we mention further in the article, mushrooms require very specific conditions in order to flourish and fruit properly. The environmental elements that you will need to consider are light direction, airflow, and temperature.
   It is recommended that you use measure the target space’s humidity with a hygrometer. Likewise, mushrooms only grow in a specific temperature range. Therefore, having a thermometer on hand will provide you with accurate readings, rather than approximations or guessing. The last thing you will need to allow for is air flow. Mushrooms use the surrounding air to breathe. Therefore, fresh air exchange during the fruiting phase is paramount.
2. Step 2: Prepare mushroom growing kit (sterilize, layer, mix). Next, you will need to get your DIY gloves on, because you will be constructing the mushroom greenhouse design kit.
3. Step 2A: IMPORTANT! Sterilize all tools and equipment. If you take anything away from this article, let it be this point. Before you begin any construction of the mushroom growing kit, it is crucial that you sterilize everything that will come into contact with the growing medium. This includes the container, the growing medium, and utensils (like sharp knives) or measurement equipment. By sterilizing everything, you will ensure no microorganisms or unwanted bacteria enters your kit. These uninvited guests can take over your mushroom spawn and will compete (and kill) your mushrooms. Additionally, you won’t know this battle is happening until it is too late, and you will have to start all over again.
4. Step 2B: Combine growing medium with mushroom spores. It is now time to combine the mushroom spores with your sterilized growing medium. It is entirely up to you how you complete this step. We like to layer the growing medium along the container, and then sprinkle the mushroom spawn around, and repeat the process with a fresh layer. This allows an even spread of the spores, for maximum colonization (and hopefully a bumper mushroom flush).
5. Step 3: Allow mushroom spores to inoculate the substrate (10 – 14 days). Now it is time to sit and wait for the mushroom spores to do their thing. During this period, it is important to keep an eye on the temperature of the greenhouse. You should be targeting a temperature range between 65 and 75 degrees Fahrenheit.
   It is during this period that mycelium forms from the spores. You will be able to recognize the growth of mycelium because they look like fine white fibers that look like miniature like roots. If you see these roots colonizing the entire growing medium, you are on the right track.
6. Step 4: Monitor indoor mushroom greenhouse for mushroom pins. After two (or sometimes three) weeks, you should be able to see mushroom pinheads (or mushroom heads) pushing their way through the surface. This is called the fruiting stage of the mushroom growing cycle. Once they appear, it will take around 7 – 10 days for the full mushrooms to form.
   It is at this point that you allow for ample fresh air exchange and maintain a humid environment. Without both, the mushrooms may not form correctly and dry out. We recommend you monitor humidity levels using a hygrometer, and if necessary, use a spray bottle to spray tap water around the mushroom caps.
7. Step 5: Harvesting mushrooms. Now for the part you have been diligently waiting weeks for, the harvest! Knowing when to harvest mushrooms will depend on the variety of mushroom you are growing. However, generally speaking, if you see the mushroom caps pulling away from the stem, you can harvest the mushrooms. To do so, use a clean sterilized sharp knife and cut the stem as close to the growing medium as possible. Now enjoy fresh or in your favorite gourmet dish.

Why Using A Greenhouse to Grow Mushrooms Makes Sense

Growing mushrooms in a greenhouse comes with many benefits. Using a greenhouse enables gardeners to grow mushrooms in a controlled and consistent environment, that can yield flush after flush of mushrooms. Let’s take a close look at the elements and benefits.

Humidity is key

One obvious benefit that mushrooms love is the humid conditions a greenhouse can create. In order for mushrooms to fruit properly, they require humidity. This is where greenhouses come into their own.

Protection from weather

Greenhouses, by their very nature, are enclosed structures that help to shield against the outside elements. This is perfect for mushrooms, that require protection from strong drafts and wind. Protection is particularly important during the fruiting stages of the mushroom growth cycle.

Easy Maintenance

Generally speaking, most greenhouses will have glass walls or windows. This is what gives a greenhouse its unique feature set of maintaining a warmth that allows for plant growth.

The transparent walls are perfect for allowing you to peer through to observe and monitor the growth of your mushrooms without disrupting them or causing any temperature fluctuations.

Warnings of Growing Mushrooms in a Greenhouse

Unfortunately, the mushroom greenhouse design also comes with a few cautions that a beginner mushroom grower should be aware of.

Indirect Sunlight

Mushroom grow set up kits do not tolerate direct sunlight. In fact, during the propagation phase of the mushroom cycle, where the mushroom spores are colonizing the growing medium, the mixture should ideally be in a dark environment.

Obviously with a greenhouse’s glass walls, a dark environment is going to be difficult to achieve. This is where we encourage our gardeners to exercise their resourcefulness, and use their out-of-the-box thinking. We recommend creating an area inside the greenhouse that is protected from direct light conditions.

Note, it is important the space still has good airflow, as stagnant air will encourage unwanted growth from other microorganisms, like mold.

Maintaining Perfect Conditions

Another issue that can sometimes develop in greenhouses are temperature and humidity fluctuations. For example, extended periods of sun can significantly increase temperatures in a greenhouse. To grow mushrooms successfully, you should be aiming for steady temperatures between 55 – 63 degrees Fahrenheit (approximately 15 – 18 degrees Celsius).

Fresh Air Exchange

One challenge that can occur with greenhouses is the lack of air flow or fresh air exchange. And even though mushrooms don’t like strong gale force winds (which tends to dry them out and inhibit growth), they do still require the carbon from the fresh air to develop properly.

By their very definition, a greenhouse is an enclosed structure, and unless windows are left open to allow fresh air to enter, the air flow is quite restricted. Of course, if you leave windows and door open in a greenhouse, it is harder to maintain temperatures and pests can infiltrate your precious greenhouse.

The best way forward, as are most things in life, is to try to maintain a balance.

Tips for successfully Growing Mushrooms in a Greenhouse

To help you along your mushroom growing journey, we have put together a quick reference list of tips and tricks to help you to achieve your mushroom growing goals.

Trays vs Logs vs Plastic Bags

There is a lot of debate among gardeners as to which method of cultivating mushrooms is best. There are pros and cons for each strategy. Ultimately, the best choice is the one you are most comfortable with. So the main takeaway here is trust your gardener’s intuition. Try out different methods from mushroom trays or plastic bags or logs, and see which one resonates with your style.

We will say, however, that we are big advocates of using sterilized equipment and medium. It would be hard to sterilize a wild log without completely ruining it. Therefore, unless you are happy to take the risk of introducing unwanted bacteria into your crop of mushrooms, we’d recommend sticking with a sterilized container like trays or bags.

Choosing the Right Mushroom Growing Medium / Substrate

There are many types of substrates that can be used for successful mushroom cultivation. You can use good quality garden soil, hay/straw, wood chips, hardwood sawdust, the hulls from soybeans and even coffee grounds.

Choosing the right growing medium will depend on what you have readily available in your area. Which ever substrate you decide, we always encourage our readers to try to reuse materials. For example, we like to take a trip down to our local cafe to pick up spent coffee grounds fresh from the days takings and mix it with another substrate like wood chips. This way, we are creating a positive impact on the environment by reducing landfill and growing our own sustainable food.

Using A Spray Bottle

We mentioned earlier that a spray bottle is a great way to manage humidity levels around your mushroom growing set up. Simply spritz some room – temperature tap water over the mushroom caps, so you can see small water droplets. Spray both day and night, and that should be sufficient for your mushrooms to mature nicely.

Managing humidity in a greenhouse

Humidity is one of the main challenges when it comes to growing mushrooms. We suggest using a spray bottle (above) to help with managing humidity. However, when growing mushrooms in a greenhouse, maintaining a consistent humidity can be even more challenging. Especially if you are growing other plants in your greenhouse. This is why we strongly recommend using a hygrometer to monitor the humidity levels and checking on it daily – especially during the fruiting stage.

What types of edible mushrooms can you grow in a greenhouse?

One of the most popular types of mushrooms to grow and eat around the world is oyster mushroom. They are one of the easiest mushrooms to cultivate and are easy to recognize due to their fan-shaped mushroom caps.

Another mushroom that you will easily recognize is white button mushrooms. These are commonly found in supermarkets, and are a fantastic beginner mushroom to grow. In fact, depending on your preference, you can grow button mushrooms as either cute small button mushrooms OR allow them to develop into larger portabello mushrooms for heartier dishes.

Another mushroom worth mentioning is shiitake mushrooms. Although they are not as common as the above two mushrooms, shiitake mushrooms are renown for their strong earthly flavors. They also have a more meaty texture, which is great for those vegetarian-converts trying to satisfy their meat cravings with culinary mushrooms.

Final Thoughts

Are you excited about beginning your next greenhouse mushroom growing project?

If so, jump over to one of our mushroom species specific growing guides for step-by-step instructions to successfully cultivating your very own DIY mushroom production.