How To Grow Mushrooms Indoors (The Ultimate Guide)

Mushrooms are easier to grow at home than you would think. Growing mushrooms has increased in popularity over the years and now grow kits are readily available in stores or online. So how exactly do you go about growing your mushrooms indoors?  

You can grow mushrooms indoors by acquiring spores and keeping them in a cool dark place. Mushroom spores need to be added to a straw, manure, or sawdust substrate to grow. Each mushroom type will require a different substrate. However, mushrooms tend to grow quickly and easily with minimal effort. 

In the rest of this article, I will discuss how to grow your mushrooms indoors. I will review how to collect your spores or utilize a ready mushroom kit. So if you want to learn more about growing mushrooms at home, read on. 

1. Select a Mushroom Type 

First, select the type of mushroom you want to grow. There are over 90 edible mushroom varieties worldwide, of which 30 are commonly grown. Each mushroom type has a unique shape, texture, and complex flavor. 

Some mushrooms, such as the beefsteak mushroom, do an excellent job mimicking meat, making them a great vegetarian meat substitute. Which mushroom you grow depends entirely on what flavor you prefer. However, if you’re just starting, there are a few easy-to-grow mushroom types. 

So what are the best mushrooms to grow at home? 

Enoki

Enoki mushrooms are fungi widely cultivated in eastern Asia. These mushrooms are known for their noodle-like texture since they grow in long skinny clumps that mimic noodles when cooked. 

Enoki mushrooms have a slight crunch when eaten, which is rare with most mushroom types. As a result, this mushroom is a staple in Japanese cooking (where it was popularized) and makes an excellent addition to most dishes. 

The enoki mushroom is relatively easy to grow, especially with a growing kit. These mushrooms are a great option if you enjoy Asian cuisine and don’t have access to these tasty mushrooms at your local supermarket. 

Oyster

The oyster mushroom originated in Germany and became a staple of many during World War I. Since that time, the oyster mushroom has garnered much popularity and is now grown commercially. 

These mushrooms are highly nutritious and promote a healthy immune system. In addition, as with most mushrooms, oyster mushrooms contain many good antioxidants, making them a highly sought-after fungus. 

Oyster mushrooms typically grow in large clusters and give the appearance of small stairs of varying sizes. These mushrooms generally attach themselves to trees or other bits of wood littering the forest. 

Shiitake

One of the most popular mushrooms to grow is the shiitake mushroom. This mushroom is used in various cuisine types and is often dehydrated for cooking purposes. Shiitake mushrooms originate from eastern Asia and are prevalent in various tasty dishes. 

These mushrooms enjoy wood decay and grow best on decomposing logs or other bits of rotting wood. Though shiitake mushrooms are relatively easy to grow, they require longer to produce mycelium; therefore, you will need to be patient. 

However, once the shiitake mushrooms begin producing, they yield quite a bit. A well-cared-for mycelium is also able to produce for years under the right conditions. So you can have fresh mushrooms for months at a time. 

White Button

Another great mushroom to grow is the button mushroom. These white mushrooms are the common round ones you purchase at your local grocery store. White button mushrooms are native to Europe and North America. 

Button mushrooms are easy to grow and are a common staple in many homes. However, these mushrooms have a higher water content, leading to rotting more quickly if stored incorrectly. 

These mushrooms grow best in a substrate of manure. Button mushrooms require a substrate that is high in nitrogen. You can purchase these mushrooms as spores, collect your own, or even purchase a ready-to-go grow kit. 

Lions Mane

Lastly, there is the lion’s mane mushroom. This mushroom is pretty cool because of how it grows in a large clump that resembles a lion’s mane. This mushroom is a member of the tooth fungus group and hails from North America, Europe, and Asia. 

Lion’s mane is known for its many health properties, promoting healthy brain aging and boosting the immune system. Some studies also suggest it could help fight and prevent cancer cells. 

Texture-wise, a lion’s mane is comparable to seafood. The texture makes it an excellent meat substitute in many vegetarian dishes. Most compare the texture to lobster or crab. However, the flavor is more earthy than fishy. 

2. Acquire the Spores 

Once you’ve chosen your mushroom variety, you can collect the spores. You will only need to collect the mushroom’s spores if you foraged the fungus you want to grow or are using grocery store mushrooms.

You can disregard this step if you plan to purchase a grow kit. Mushroom kits are easily acquired online. Oyster mushrooms are the easiest to grow if you’re leaning toward using a kit.  

Collect the Spores

Collecting mushroom spores isn’t as tricky as it sounds. On the contrary, the process is surprisingly simple. However, you will need a few items to successfully collect the spores necessary for growing your fungus at home.

You’ll need:

  • A mushroom cap 
  • A piece of paper 
  • Water 

Here’s how to collect mushroom spores for growing:

Inspect the Mushroom for Flaws

It’s essential to ensure the mushroom is healthy and not rotting. A rotten mushroom is less likely to produce healthy spores. Instead, you can end up with mold in your growing container. You want a mushroom that feels firm and not mushy. 

Remove Its Stem

Remove the mushroom stem from the cap if the stem is in the way. You want to ensure nothing is in the way of the underside of the mushroom cap.

The gills of the mushroom are where the spores are. If the mushroom cap hangs down over the spores, you can also trim it back a bit for better exposure of the gills. 

Lay Out a Piece of Paper

The paper is used to make a spore print of your mushroom. You can cut the paper into small squares for easier storage or leave it whole where the mushroom imprints are where the spores will be. Just make sure the paper covers the entire size of the gills.

Press the Gills on the Paper

You’ll then place the mushroom cap gills down on the paper. The gills must fully come in contact with the paper to properly transfer the spores. Mushrooms will automatically start releasing spores within about 24-48 hours. So it’s essential to be patient. 

Drip Some Water on the Cap

Adding water aids in the release of mushroom spores. However, you mustn’t get the paper wet, only the mushroom cap. Using only a few drops of water is best. 

Cover the Mushroom Cap and Wait

You can use a bowl, cup, or plastic wrap to cover it. You want to ensure the mushroom doesn’t dry before it imparts its spores onto the paper. The cover doesn’t need to be airtight, just protection against the air. 

Remove the Cap

Under the cap should be a light print of the mushroom’s gills. This mushroom print will contain tiny microscopic spores that you can use to plant new fungi. 

Store the Print (Optional)

Once you have your print, it can be stored for up to 6 months or used to grow mushrooms immediately. After a year, most spores will have died off and cannot be grown easily. However, most mushrooms grow pretty quickly once the mycelium appears. 

Also, button mushrooms will be the easiest to acquire from your local grocery store and make a good mushroom print if this is your first spore print. 

Fun fact: You can extract dried mushroom spores from some varieties, and they will grow.

Purchasing a Mushroom Grow Kit 

If you’re hesitant to harvest and grow mushroom spores, don’t worry. There are several companies who have already done it for you and you can purchase grow kits from them. There are many different grow kits on the market, some of which contain unique mushroom spores.

The most popular mushroom to grow from a kit is the oyster mushroom. Mushroom grow kits are fantastic because they require very little work or preparation on your part. The mushrooms arrive in something like a rectangular box with a punch-out door on the front. 

You can grow this mushroom in 4 easy steps:

  1. Open the grow panel door. 
  2. Soak the kit overnight.
  3. Mist with water daily. 
  4. Wait 10 days to harvest.

Mushrooms kits are guaranteed to grow and produce harvestable mushrooms in only 10 days. Usually, each kit will produce about 3-4 mushroom harvests before dying out. Utilizing a grow kit is an excellent way to get a feel for mushroom growing, especially if you’re just starting to grow mushrooms. 

Besides oyster mushrooms, you can also get growing kits for other mushrooms like lion’s mane, shiitake, or Cordyceps militaris.

3. Select a Container to Grow Your Mushrooms In

You must also select a suitable container to grow your mushrooms. You can ignore this step if you have purchased a mushroom grow kit, as one is provided to you.

Generally, a tub or bin is best for growing mushrooms since they have enough room to add more substrate after the mycelium grows. 

Typically, you’ll want your container to measure 14 x 16 inches (35 x 40 cm) and 6 inches (15 cm) deep. These measurements are ideal for most types of mushrooms.

The container used can be made of practically anything, the most popular material being wood or plastic. However, there are other types of containers mushrooms grow well in. 

Another popular growing method is using a substrate bag to grow your mushrooms. Some mushrooms can be grown on logs, roots, or other dead pieces of wood. Which container you use depends entirely on the mushroom type you wish to grow. 

4. Sterilize All Containers, Substrate, and Tools 

It’s crucial to sterilize your mushroom-growing container, substrate, and tools. To sterilize the tools and container you have chosen, rinse them with hot or boiling water. This method will quickly kill off any harmful bacteria and prevent unwanted mold growth when growing your mushrooms. 

Keeping your hands clean is also essential when working with your mushroom spores, container, or substrate. You want to minimize contact with contaminants and bacteria that will thrive in your mushroom’s moist substrate.

You will also need to sterilize your substrate if it doesn’t come pre-sterilized. Luckily, this process can be done relatively quickly. There are a few different methods for substrate sterilization. However, one method is much simpler. 

These are the items you will need:

  • The bag of substrate you need to sterilize
  • A pressure cooker
  • Water 

Now, here’s how to use hot water and a pressure cooker to sterilize your substrate:

  1. Put the substrate into a pressure cooker. The pressure cooker should have enough water to cover the substrate. The substrate can stay in the bag or be transferred into smaller bags for cooking. Make sure the substrate and water don’t go more than 2/3 of the pressure cooker to allow the steam enough space to build up.
  2. Kill off bacteria with cooking. Cook the substrate at 15 PSI (103.4 kPa) for 2 ½ hours to ensure all bacteria are killed. Without boiling water, some bacteria will survive, which is why two hours of cooking is ideal. 
  3. Turn off the heat after 2 1/2 hours. You don’t want to overcook the substrate and end up melting the plastic bags. 
  4. Allow the bags to cool. Let the bag sit for at least 12 hours. After they have heated, the bags need time to cool before being handled or used for growing. 
  5. Use when ready. Once the substrate bags have cooled, you can use them immediately or wait a few days. However, if you open the bags and leave them, you might have to re-sanitize them later. 

If you’re a visual learner, I recommend watching the Mossy Creek Mushrooms YouTube video on sterilizing mushroom substrate. He does a great job of walking you through the process and explaining the sterilization as he goes.

5. Select an Appropriate Substrate 

Another essential step to growing mushrooms is selecting the appropriate substrate for your variety. Some mushrooms require manure, dead wood, or straw.

Shiitake mushrooms prefer dead wood, so they will grow best on an old log, while white button mushrooms will thrive in horse manure. 

The most common mushroom substrates include:

  • Straw
  • Hardwood sawdust
  • Manure
  • Vermiculite
  • Soy hull
  • Coffee grounds

Most of these substrates can easily be acquired at your local florist, around your home, or at a farm supply store. You can also purchase most substrate types online, and if you purchase a mushroom grow kit, the substrate is generally included. 

Also, for hardwood substrate, if you’re crafty, this can be foraged or found around woodworking shops. Just ensure that you sanitize any materials you find before growing mushrooms on them. Otherwise, you can accidentally introduce bacteria to your mushroom grow container. 

If you’re sensitive to strong smells, growing button mushrooms will be harder for you indoors. However, oyster or shiitake mushrooms are a superb indoor choice that produces minimal smells. Plus, these mushrooms are great to have on hand and can easily be dehydrated for later use. 

Suitable Mushroom Substrates to Order

Having a suitable substrate for your mushrooms is essential. There are many different mushrooms, all of which have unique substrate needs. However, easy-to-grow mushrooms, like oyster mushrooms, are less picky.

So If you want to get a mushroom substrate from your local retailer or online, I’ll recommend a few options below.

Be sure to check whether it’s suited for the type of mushroom you envision growing:

Clean Processed Straw

Straw is a common growth medium for mushrooms. Oyster mushrooms need a straw to grow healthy, and straw is easily acquired. However, it’s essential to ensure that your straw has been sterilized. Otherwise, it can be a breeding ground for bacteria. 

Mixed Mushroom Substrate

If you want a substrate geared specifically toward mushroom growth, then a mixed substrate is perfect for you. A pre-mixed substrate is rich in nutrients, ensuring mushrooms grow well in this medium. 

Mushroom substrates include ingredients such as:

  • Premium manure
  • Vermiculite
  • Coco coir
  • Gypsum

Soy Hull Pellets

Another common substrate is soy hull pellets. These pellets are great for mushrooms like oyster mushrooms, which grow well on many mediums. Soy hull works well but often yields slower mushroom growth but more mushrooms. 

6. Pour the Substrate Into the Growing Container 

Your mushroom-growing container should measure about 14 x 16 inches (35 x 40 cm) and 6 inches (15 cm) deep.

Once you have your substrate, you will need to pour about 3-5 inches (7.6-12.7 cm) into the container. You want to leave some room at the top to add more later when the mycelium begins to grow. 

Wash your hands with soap and water and be careful not to handle the substrate for too long to avoid contamination. You can even wear sterile gloves when pouring the substrate into the container. It’s easy to accidentally grow bacteria in your grow container if you’re not careful.

7. Extract the Spores Into the Substrate

Once the substrate has been spread out, you’re ready to transfer the spores into the growing container. Extracting mushroom spores from a print is simple and requires only a few items. Just ensure that your print is pretty fresh and handle it with care. 

You will need:

  • A mushroom spore print 
  • An Exacto knife or other sharp knife 
  • A face mask (wearing one is a good idea since you can’t see mushroom spores) 

Here’s how to extract mushrooms spores into substrate:

Get Your Spore Print

Prepare your mushroom spore print. Ensure you handle it carefully, as you don’t want to disrupt the spores accidentally. Refrain from touching the print on the paper with your fingers or hands. 

Scrape the Print With a Knife

Use an Exacto knife to scrape the paper where the print is. It’s essential that you do the scraping over the substrate, so the container catches all the spores. Gently scrape the entire print until you feel most of the spores have been removed. 

Discard Old Prints

Once you have scraped all the spores off, the old print will no longer be of use. 

As you can see, extracting spores from a print is relatively simple. However, if you’re growing your mushrooms from a kit, this process will have already been done for you. Also, your growth instructions will vary. 

It’s important to remember that mushroom spores are tough to see, and it might feel as if you’re scraping nothing into your substrate. However, you most likely are, and your mushrooms will grow as long as you provide proper care. 

8. Moisten the Substrate 

Once the spores have been successfully extracted into the substrate, the growing medium will need to be moistened. Mushrooms require damp environments to grow well, requiring daily watering. 

However, you should never use a watering can or pouring method to dampen your mushroom spores. This kind of direct water is too harsh and can result in overwatering the spores. Instead, a fine-mist spray bottle is best to keep the substrate wet. 

Your mushroom spores will need to be misted daily to grow and thrive. A watering schedule is ideal so that you don’t forget. If your spores don’t receive enough moisture, they are less likely to grow. 

9. Incubate the Mushroom Spores 

Spores that have been sprinkled with water now require incubation. The spore growth phase is the most crucial for your mushrooms. During this growth phase, the spores work to create a mycelium, which acts as a sort of root system your mushrooms will grow from. 

To incubate your mushroom spores, keep them at 70 °F (21 °C) for about 3 weeks. You can ensure the temperature remains correct by utilizing a heating pad or placing them in a room that is slightly warmer in your home. Inserting a thermometer into the substrate will help you get a more accurate read on the substrate’s temperature. 

For the mushroom spores, during the first part of their lives, they must be kept at a warmer temperature, after which they require the temp to be dropped for the edible fungus to grow. However, incubation is a crucial first step in the overall growth process. 

10. Drop the Substrate Temperature 

After about 3 weeks, or after the mycelium has appeared, you’ll drop the mushroom substrate’s temperature. The mycelium will be white in appearance and spread out across the substrate. This strange root-like system is what will grow the mushrooms. 

Once the mycelium appears, drop the substrate temperature from 70 °F (21 °C) to around 60 °F (15.6 °C). You can do this easily by turning down or turning off the heating pad and adjusting your thermostat. 

At this phase, you will also need to add a thin layer of the substrate to cover the mycelium. The substrate covering will help insulate the mushrooms and keep the mycelium safe. About an inch (2.5 cm) of substrate will work just fine.  

If you notice mold forming at this stage, the mushrooms will not be viable. Mold means there has been some contamination along the growth process, and you will need to start over. Mold can be dangerous, so it’s best not to risk eating mushrooms that develop mold. 

11. Care for the Mushrooms as They Grow

Once your mushroom’s temperature has been lowered, you’ll have to wait. During this waiting period, you must regularly water your mushrooms and monitor for mold growth. Eventually, you will notice tiny mushrooms popping through the surface of the substrate. 

Your mushrooms should be placed somewhere cool and dim to grow, like in a closet or away from windows. Mushrooms don’t require complete darkness to grow, and many need a little light to promote healthy growth. However, your mushrooms will struggle if placed in harsh sunlight. 

It’s essential to ensure your mushrooms don’t get too warm, as this can lead to molding and a poor fruit yield. Monitor your substrate’s temperature carefully and adjust it as needed.

Depending on the mushroom, once the mycelium has shown up, you will have harvestable mushrooms in as little as 10 days

12. Harvest Your Mushrooms 

Finally, after all your hard work, you’re ready to harvest your mushrooms. Each mushroom variety will have a slightly different growth time, but you can tell when your mushrooms are mature by how they look. 

When the mushrooms grow more prominent and appear mature, they likely are. Still, consulting your grow kit or the internet on the type of mushroom you are growing is a good idea. You don’t want to harvest your mushrooms too early. 

Common Mushroom Grow Times

The most common mushrooms to grow and their growth times:

Oyster

Oyster mushrooms typically grow in 10-14 days, making them one of the easiest and fast-growing varieties of mushrooms. If you’re struggling to grow your oyster mushrooms, there’s something likely wrong with the spores, or they are too old. 

Shiitake

The shiitake mushroom usually takes longer to grow. If grown on wood, they grow around 6 months. However, they will take about 8-12 weeks to produce harvestable mushrooms on sawdust. 

Lion’s Mane

Typically, lion’s mane mushrooms grow in 7-14 days once colonized. You can easily grow this mushroom at home, though it’s highly susceptible to mold if not observed. 

Enoki

The enoki mushroom generally takes 2-4 weeks to grow and become harvestable. Once established, these mushrooms multiply and will provide an excellent source of nourishment. 

White Button

Growing white button mushrooms usually takes about 1-2 weeks. However, these mushrooms can easily be grown using store-bought mushrooms if you create your spore print. 

Cordyceps militaris

Cordyceps militaris mushrooms are unique and take about 4-6 weeks to grow but are well worth the wait due to their medicinal properties. These mushrooms are also a tasty addition to most dishes. 

How Harvesting Works

To harvest your fully grown mushrooms, simply place your fingers at the base of the mushroom and slowly twist. This motion will eventually release the mushroom, and you will be able to sever the tiny strands of mycelium attached.

Ensure you’re careful not to damage the mycelium, as it’s the mushroom’s root system. If you damage the mycelium, it can prevent future mushrooms from forming, and you will have to start the whole growth process again. 

It’s important to note that some mushrooms will continue to produce regular harvests while others will die off after 2 or 3 harvests. How long your mushrooms grow depends on how well they are cared for and the type of mushroom. 

Also, there are many types of mushrooms and most can be grown indoors so long as you know what to do. Using a kit is easiest but most mushroom spores can be collected and grown all on their own. 

Is It Safe to Grow Mushrooms Indoors?

Mushrooms make a tasty addition to most culinary creations, and it’s only natural to want to grow your own. Plus, growing indoor mushrooms is pretty simple. So is it safe to grow mushrooms inside your home? 

It is safe to grow mushrooms indoors. However, you need to take some precautions, as mushroom spores travel. Placing your mushrooms in a space with good ventilation is important and wearing a mask when handling spores is essential. Typically, mushrooms can grow indoors without harming your health. 

So as long as you are careful, you shouldn’t have a problem growing mushrooms indoors. You will want to be vigilant in watching for mold and careful when handling spores. If you are still worried, you can always grow them in your garage or a less frequented room in your home. 

What Mushrooms Are Easiest to Grow Indoors?

If you’ve never grown mushrooms indoors before, it’s best to start with an easy variety. There are a few different mushrooms that grow well indoors. However, one mushroom type grows the very best. 

Oyster mushrooms are the easiest to grow indoors. The oyster mushroom is highly resilient and can grow on several substrates like straw, sawdust, and coffee grounds. The oyster mushroom is available in several varieties of ready-to-grow kits. 

These mushrooms are widely available in grocery stores and online. They are frequently used in many culinary creations for flavor and health benefits. These mushrooms multiply. Usually, you can expect to harvest them after 10 days.  

Do Mushrooms Need Light to Grow?

Caring for mushrooms is simple since they require little time and energy. They require moisture and cool temperatures to survive, but what about sunlight? Do mushrooms need light to grow and produce more mushrooms? 

Mushrooms do not need light to grow until they are ready to produce fruit. However, mushrooms do not enjoy harsh direct sunlight and require very little light to produce healthy mushrooms. Therefore, dim or indirect light will be enough to aid your mushrooms in producing healthy edible mushrooms. 

As you can see, your mushrooms will do quite well indoors. You should keep them out of direct sunlight, as too much heat will kill the spores and mycelium. Placing the growing container near a light source is great, but keep them out of direct sunlight. 

If you enjoy growing mushrooms at home, you can use growing bags.

Conclusion 

Growing mushrooms indoors is extremely simple, and fun mushrooms grow more quickly than any other food source. Plus, they are relatively low maintenance compared to garden crops. You simply have to select your mushroom type, substrate, and container, then get growing. 

If you want the growth to be even simpler, you can purchase a ready-to-go mushroom growth kit. These kits are great for beginners, though they are limited in the type of mushrooms they offer.

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of TheGrowingLeaf.com, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

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