How To Grow Mushrooms Indoor – Step By Step Guide

Mushrooms are much different from the other veggies we eat. And chomping down on them during lunch is always a delight. But can you grow mushrooms yourself?

Yes, you can, and it’s pretty simple if you know how to go about it. However, be warned, as it’s not the same as growing plants. It’s a lot different, and without the right tools, you’ll end up with a bad batch. 

It’s not just that. Mushroom spores can be inhaled and cause allergies. These allergies can range from mild to severe. 

So, how do you grow mushrooms at home? Do different types require different care? How easy is it? And most importantly, what type of substrate do you need? 

We will answer all this and more in our ultimate guide on how to grow mushrooms indoors.

How Hard Is It To Grow Mushrooms?

Sow the mushroom seeds, and you’re on your way. The process should be as simple as growing a plant. But in reality, it’s far more complicated. 

For one thing, mushrooms don’t have seeds. And while plants still require a lot of care and attention, mushrooms are an even worse case. 

But first, let us learn how mushrooms are grown. 

How are Mushrooms Grown? 

grow mushroom indoor

Many people are of the impression that mushrooms are plants, but they are not. They aren’t even remotely considered plants. Mushrooms come from an entirely separate kingdom, as distinct from plants as plants are from animals – fungi. 

The main difference is in their cellular structure, which is long and filamentous instead of the usual oblong shape. These are called hyphae, and in most species, they overlap to form larger structures called mycelia.

Fungi, and mushrooms, in particular, reproduce by creating spores instead of seeds. These spores are so tiny that you can’t view them with the naked eye. 

Luckily, they won’t grow on human skin. So, you don’t have to worry about accidentally catching some. But they grow in unconventional substances, such as hardwood sawdust, potting soil, and grains. A collection of these substrates, along with the mushroom spores, is called “spawn”; you can find some in stores.

Spawn is the primary source of mushrooms for most mushroom growing individuals. The spawn itself can support plenty of growth. But you would want to dump it into a different medium for growing mushrooms indoors.

So, how hard is it to grow mushrooms at home? Here are a few things that could make a difference:

The Type of Mushroom:

Much like plants, animals, and other forms of culture, each mushroom requires individual care. Oyster mushrooms are by far the easiest for mushroom growing. And many people who cultivate mushrooms at home start with these.

Shiitake mushrooms are also easy to grow and cultivate. Some rare mushroom types, such as Chanterelle and Porcini, are much more challenging to grow. This is because many don’t grow all year round, and some only grow in specific spots. So, finding spawns of these mushrooms is either impossible, complicated, or expensive.

There are parasitic fungi, which aren’t actual mushrooms. They grow on either living creatures or other mushrooms. The most common example is the Lobster Mushroom, which not only fruits in the fall, but is also a parasite. Growing mushrooms like these can be tricky since they require a secondary host.

Morel mushrooms, formerly known as Morchella, are impossible to grow indoors and need to cultivate from the wild.

The Environment:

Next, you have to consider the environment for mushroom growth. Again, this is tied to the type of mushroom since each species requires specific critical care. Much like other fungi, mushrooms prefer dark, clammy, and humid areas. You can either pump in humidity using a plant humidifier or grow mushrooms at home in a grow tent. Here is a list of the best grow tents on the market.

They don’t like heat, though. Therefore, the temperature must be between 55 and 60 degrees Fahrenheit. While some species may require even lower temperatures. Unlike plants, they don’t prefer sunlight. It’s not that they don’t need it – they purposely stay away from the sunlight.  

However, mushrooms that grow on top of logs and are exposed in the wild won’t have an issue. You can also use a grow kit, which is much easier.

Most Popular Types of Mushrooms to Grow:

So, we’ve established that growing mushrooms can be easy and hard. That depends on the type of mushroom you’re growing. But which type is the best? What should you try out as a starting mushroom cultivator? Here are a few popular choices: 

Shiitake Mushrooms

Shiitake Mushrooms: 

You probably saw this one coming. Shiitake mushrooms have become a celebrity in the mushroom world. They’re the most common type of mushrooms grown anywhere in the world, second only to the white button.

Shiitake mushrooms are pretty peculiar in how they grow, or rather where. They grow on logs instead of in the ground. You’ll need to cut logs from hardwood trees and make sure the wood does not infest with any other fungus. They’re susceptible to invasions by other parasites.

White Button and Field Mushrooms:

White Button and Field Mushrooms

The white button and field mushrooms are the most common types of mushrooms. White buttons, in particular, are easy to grow. They grow all year round and don’t require any sunlight. You need to buy the spawn and start the journey.

White buttons are grown in manure that is rich in nitrogen. So, horse manure should be your best bet. They should grow in the span of about a few weeks. 

Field mushrooms are similar in that they grow in cow or horse manure.

Oyster Mushrooms:

Oyster Mushrooms

Oyster mushrooms are starting to take the place of Shiitake and White Button. They are becoming popular due to how easy they are to cultivate. They grow in straw, which is readily available, and can be combined to form a spawn. 

The main problem is that the straw is acquired unclean, and you need to pasteurize it before using it. That’s not too hard though. Heat it to 100 degrees C for half an hour in a water bath. 

They grow in dark spots that retain a lot of moisture. Your basement is a great choice, but sealing off a corner of a room with plastic wrap should work too. You can use Coco coir, mixed with vermiculite as a growing medium

Large fresh raw portobello mushrooms

Portabello Mushrooms: 

Portabello mushrooms look like bigger, fatter white buttons. These are the final, fully-developed stages of white button mushrooms’ life. So, growing them is as easy as growing white buttons.

They’re cultivated for their large size and meaty texture, as well as for their aesthetics. However, Portabello mushrooms are normally baked and not fried, unlike white buttons. This makes them a delicacy to have at any dinner table.

Cremini Mushrooms: 

Cremini Mushrooms

Another variant of the white button mushroom, the Cremini, is a brown version of the same species. The cremini variant first came to exist, and the white version is a mutation that has become more famous.

Because of this, growing them is no different from growing white buttons. They grow in horse or cow manure or any other substrate that is rich in nitrogen. And they have a similar taste and texture.

Chanterelle Mushrooms: 

Chanterelle Mushrooms

Here’s something for those who like to prefer value in their meal. Perhaps the most sought-after mushroom species, Chanterelle Mushrooms, are a delicacy. They are not rare but can be hard to grow. So, only go for these if you have adequate experience in the mushroom-growing culture.

They are available in the wild but can be cultivated via store-bought or homemade spawns. However, you must be extremely careful with this species. There are two lookalikes to this; the false Chanterelle and the Jack-o’-Lantern. Both these are poisonous and can cause diarrhea and stomach cramps. They last longer than other mushrooms (10 days) and look and taste incredible.

How Do I Start an Indoor Mushroom Farm – Step by Step: 

Now that you know everything about mushrooms, it’s finally time to grow some! While the journey can be pretty frustrating and, many times, time-consuming, the result will always be rewarding.

Nevertheless, here we list down all the steps to grow mushrooms at home in the most common way: 

1. Decide on a type of mushroom:

This is by far the most critical part. You must choose a type of mushroom that is easy to grow and won’t cause difficulties. People who have more experience can decide on more complex species of mushrooms. Choose one that can also be used in the food you want to cook. Each type has its taste and texture.

2. Purchase the Spawn: 

Spawn is a collection of the mushroom’s spores along with some substrate to preserve them. You will need to get the growing medium separately as well. Or you can make your spawn, in which you can dump the spores onto the substrate. But for beginners, purchasing the spawn is the easiest way to grow.

3. Gather the Substrate: 

Now, you need to gather a more growing medium to grow the spawn. You can use the same type of substrate that the spawn uses, or you’ll have to make your own. Luckily, mushrooms aren’t picky and can grow in a homemade substrate. So, you won’t have to make any purchases at this stage. Gather your straw, hardwood sawdust, wood chips, potting soil, or manure, and lay it out in a tray.

how hard is it to grow mushrooms

4. Pasteurize the Growing Medium:

Before you continue to cultivate the mushrooms, you must eliminate all competitors. And that means heating the substrate to kill off any microbes or competing fungi. This is important when you consider the fact that parasitic fungi exist. 

Pasteurizing can be done in your microwave, or by heating over a water bath. Heat the substrate for about two minutes in the microwave. This is the equivalent of heating it to up to 200 degrees Celsius. All of this should be done before burying your spawn in. 

5. Heat the substrate:

Now that you’ve sterilizedsubstratetrate, you still need to keep it warm to promote mushroom growth. Use a large baking tray to spread the spores out, and heat it to about 21 degrees Celsius. This is what most mushrooms thrive on, though you should research into that specific to your species.  

6. Place substrate in the Right Environment:

It’s time to choose the right environment. Most mushrooms grow in dark, damp, and cold environments. Keep the temperature about 55 F (13 C), and keep the tray in a humid place. A basement or under the sink are good places, though you can cover a corner in plastic wrap as well.

7. Wait and Harvest: 

The time it takes for the mushrooms to develop varies, but it should take about two to three weeks. Keep checking on them to make sure they’re growing, and don’t harvest them before time. That’s the worst you can do. Also, ensure the temperature and humidity are maintained throughout. 

Alternative Methods Of Growing Mushroom

Here are two alternative methods of growing mushrooms if you don’t want to use the traditional method.

1. Coffee Ground Method

coffee ground method for growing mushrooms

If you want an easier alternative to growing mushrooms at home, you can try this other method. It’s a cleaner and much more pleasing method of harvesting mushrooms. And it’s convenient too. 

1. Collect the Coffee Grounds: 

Since coffee grounds are readily available, you can jsust collect it from your local coffee place. Grounds are a great substitute for substrate. And in many cases, the mushrooms may thrive better in the grounds than in a substrate. 

You will also need to decide how many grounds you need. If you want 500 grams worth of mushroom spawn, you should get or buy 2.5 kilos of coffee grounds.

The general ratio is 5:1 for a coffee-to-mushroom spawn. You might need more if it will take more than 3 weeks for the spawn to grow.

2. Purchase the Spawn and a Container: 

Next, you’ll need to buy the right spawn, and find a suitable container. You can use your baking tray, but some people prefer to use a filter patch grow bag. Find this near the same spot in the store where you had found the spawn. 

Make sure to sterilize the container before you use it if you’re using an old one. Sterilize it enough, so you know there aren’t any bacteria or fungi present on it. If this is a container you’ve previously used for growing mushrooms, wash it thoroughly.

3. Transfer and Place in the Right Environment: 

Now simply transfer your spawn into the container with the coffee grounds laid out. You won’t need to sterilize the grounds, since they most probably haven’t been near any fungus. You can use spent coffee grounds, preferably one acquired directly from a café or a bag of grounds. 

Choose the right environment for your spawn to develop. A cold, damp, and dark environment is suitable. But that heavily depends on the type of mushroom you’re trying to grow. It should be noted that this method cannot be used for mushrooms that grow on logs. 

4. Relocate and Mist:

Now, this is the part that’s different from the conventional method. As soon as your spawn turns completely white, transfer it to a new location. This location should be brightly lit, but not under direct sunlight. Cut a small hole into the surface of the growing medium and lightly mist it with water. You will have to do this twice a day since the grounds will now start to dry out.  

5. Wait and Harvest:

growing mushrooms on logs

Once done relocating, you now have to wait for the mushrooms to start fruiting. This should take between two and three weeks, though some species take longer. If you’re feeling hopeful, you can continue to use the same grounds for growing the same species of mushroom. But all the nutrients will have most likely been sucked up by the first batch.

2. Growing Mushrooms on Logs: 

Some mushrooms, such as the common Shiitake mushrooms, require you to cultivate them on logs. If that’s the case, you will have to first find an appropriate log. You can cut one yourself, or buy one. Choose one that’s between 3 and 4 feet in length, and should be at least 2 weeks old. This will ensure the tree’s mushroom-repellent properties have faded away.

Drill two-inch deep holes all across the log in a diamond pattern, and plug the holes up with birch plugs. The birch plugs need to have been previously colonized by the mushrooms, typically in the same manner as the previous ones. 

Is It Safe to Grow Mushrooms Indoors?

When it comes to growing mushrooms indoors, there’s not a lot of stuff that can go wrong. Right? Well, yes. Growing mushrooms is a fun activity, and since the species aren’t poisonous, you won’t need to worry about infections. 

And like we already established, the spores don’t grow on your skin, as the conditions won’t be ideal. However, there is one place in your body where they can very easily culminate – your lungs. 

The thought seems morbid but thinks of it – the environment is perfect. It’s warm for starting the growth, moist, and dark. There are many cases of people inhaling these spores. Fortunately, due to a lack of nutrients, the mushrooms don’t fully grow. But the small growths can still cause flu-like symptoms. And that’s in the mildest of cases. 

You can simply combat this by wearing a surgical mask and installing a HEPA filter air filtration unit. The symptoms will be mostly like those of an allergy, but in severe conditions, you might face adverse health issues.


Growing mushrooms indoors is a fun activity, and the results can be more than rewarding. Mushrooms tend to grow in cold clammy environments, away from the sun and predators. Growing mushrooms at home require just as much love and care as plants do. 

In this guide, we took a look at mushroom varieties, the substrates, and how you can grow your own. We also looked at how dangerous mushroom spores can be, and what precautions you can take against them. 

Regardless of what method you choose, or what species you want to grow, there’s one last thing you’ll need – patience. Mushrooms take some time to grow. The estimated time is about two weeks, though many species can take longer. 

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