How to Grow Mushrooms at Home: Indoor and Outdoor Growing Guide


If you’re looking to start growing mushrooms at home, you need to know a bit of information before getting into this unique cultivation. It’s only with a good foundation of basic mushroom knowledge that you will be able to grow them successfully.

Growing mushrooms at home, indoors or outdoors, can be easy as long as you have viable spores, a damp and dark environment, and a suitable container. When properly maintained, mushrooms can continue to grow for years, with the same initial substrate providing up to three flushes of mushrooms.

Whether you want to grow mushrooms indoors or outdoors, this guide will provide you with all the essential information you need to know to grow mushrooms successfully right at home.

Six Important Things to Consider When Growing Mushrooms

Photo by Paul Nguyen

How Hard Is It to Grow Mushrooms at Home?

Growing mushrooms at home can actually be pretty easy. Those who tell you otherwise may just be a bit lazy because it isn’t so much that it is hard to grow mushrooms as it is labor-intensive. The intensity of the labor depends on the growing method or mushroom variety you choose. There are also several readymade kits now available on the market, which help make growing mushrooms at home easy and not labor intensive at all.

Beyond that, growing mushrooms takes time and requires patience. So, if you are someone who hates waiting for things, then perhaps waiting for mushrooms to grow will be hard for you.

The only real way that this becomes hard to do is when you fail at it—repeatedly. Growing mushrooms is a skill that takes some practice, but the number one reason for fungi failure is simply lack of research.

However, you’re here doing research right now, so this won’t be the case for you.

Is It Dangerous to Grow Mushrooms Indoors?

It’s common to think growing mushrooms indoors could be dangerous, but it isn’t. Some people think of fungi and automatically translate that to mold. Understandably, this would lead to concern, but mold is just a type of fungi; other fungi include lichen, truffles, and yeast.

Growing mushrooms in a controlled environment under your loving care is perfectly safe. The consideration of safety comes in choosing a variety, as not all mushrooms are safe to eat.

Now, if you find mushrooms growing indoors—like Leucocoprinus birnbaumii in your houseplants or anything in your bathroom, for instance—then that is potentially dangerous. Not for your houseplants with the former, though they are toxic if ingested. Bathroom fungi means mold is almost certain to be present, and that’s something you should look into.

Key Supplies and Equipment Needed to Grow Mushrooms

To grow mushrooms, you need viable spores in the right medium under the right conditions. The particular supplies and equipment you’ll need will vary slightly depending on the method you chose. For example, a drill and hammer are necessary for log inoculation. A covering for shade may be required when growing outdoors, and you may need a humidifier to control an indoor environment.

If you’re looking to start cultivating mushrooms as a full-time hobby, you’re likely to own items like cheese wax, syringes, and mason or agar jars in bulk.

Perhaps the most helpful piece of equipment you may want to have is a pressure cooker. This is often utilized for sterilizing or pasteurizing items like tongs, growing containers, base liquids for cultures, or substrate. Obviously, you can find ways around this as there are other methods for sterilizing and pasteurizing, but a pressure cooker will make things easier.

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Jalape_o_Pepper_Lines (4)

Do You Have to Buy Specialty Equipment to Grow Mushrooms?

Many mushroom supply shops have various containers and fancy setups to grow mushrooms in, but these can often be expensive and, quite frankly, unnecessary. These items may have bells and whistles like an air filter feature that’s built in, but again, these aren’t things in which you need to invest in to be successful at growing mushrooms. As we will soon discuss, you can grow mushrooms using simple household items like toilet paper and plastic bags.

That isn’t to say, however, that you shouldn’t purchase such products. Many of these items can be helpful and certainly practical, and if you’re going to become a long-time mushroom grower, they would pay-off. The point is you can use whatever you want that works. This is your project, so do it how you feel most comfortable.

Most Popular Varieties of Mushrooms to Grow

Dozens of mushrooms can be grown at home, though some are easier to grow than others.

The three most popular varieties to grow are oyster, button (white caps), and shiitake. These three are also some of the varieties most favored by beginner mushroom growers.

Easy to Grow Mushroom Varieties

Other easy and popular mushroom varieties include:

  • Brown Caps
  • Portobello
  • King Stropharia aka Garden Giant
  • Velvet Pioppini
  • Pearl Oyster
  • King Oyster
  • Enoki
  • Wine Caps
  • Lion’s Mane

Difficult to Grow Mushroom Varieties

Unfortunately, not all mushrooms are easy to grow. In fact, some of the most popular gourmet mushrooms used worldwide are still only found in the wild because cultivation is so difficult. This is due to the type of fungi these mushrooms are and how they interact with their environments.

There are three broad categories of mushrooms. The varieties you grow at home will generally be what’s known as saprophytic fungi. They feed on decaying matter, and their natural environments are easy to mimic.

Parasitic fungi are, as you might guess, mushrooms that feed on and attack living organisms. This ecology puts a strain on cultivation. Examples include Cordyceps Sinensis and Honey Mushrooms.

The third group, called mycorrhizal fungi, grows via an exchange of nutrients with trees and other plants. There is a complex relationship between the mushroom mycelium and the tree roots that is yet to be fully understood, making cultivation exceedingly difficult, if not impossible. Some well-known varieties of this type of mushroom are:

  • Porcini
  • Truffles
  • Aspen Bolete
  • Lobster Mushroom
  • Hedgehog Mushroom

Regardless of which mushrooms you decide to grow, always get spore from a reputable supplier.

Can You Grow Mushrooms Using the Ones You Bought at a Grocery Store?

Photo by Barmalini

Yes, you can grow mushrooms using varieties you bought from a grocery store. However, it should be thought of more as making a clone, as you are essentially regrowing a copy of the parent fungi. This is similar to re-sprouting a scallion or green onion by putting the bulb and roots in water. In fact, growing mushrooms this way is quicker than growing from spores because you already have the mycelium.

In the way plants have seeds, mushrooms have spores, also called spawn or inoculum. Under moist and humid conditions, these spores become mycelium, which branches out to feed and eventually fruit. The mycelium bunches up to form a platform for growth (in biology, known as a primordium), and mushrooms are then formed.

The mycelium and primordium can still be found at the stem of harvested mushrooms where they were in contact with the soil. This is what is used to create a clone of the mushroom.

We will take a look at how to do this a little later on, but first, we need to consider the needs of a mushroom and what kind of environment it requires to grow.

Key Environmental Requirements to Help Your Mushrooms Thrive

You can use several different methods to grow mushrooms at home, and the internet is filled with an overwhelming number of options that can make it difficult and confusing to know what to do. Regardless of how you grow your mushrooms, the basic needs are the same. Understanding these concepts is the foundation to successful, home-grown, edible fungi.

Mushrooms and Light

Unlike plants—which contain chlorophyll and need sunlight for photosynthesis—mushrooms require a dark environment to spawn. That being said, some light will not harm growth, but a darker setting is better during the first growth stages.

A dim light is needed to form fruit bodies, and only a few hours a day of light is enough for successful fruiting. If you are growing mushrooms indoors, either indirect sunlight or a fluorescent lamp is fine. When outdoors, protect mushrooms with a shade covering or place them in a shady area of your garden to grow.

Mushroom Moisture Levels

Moisture is required for mushrooms to produce their fruit, but not through the water in the substrate alone. Mushrooms need to breathe, and soaking mushrooms (i.e., keeping them wet rather than moist) can essentially choke them to death by way of anaerobic bacterial buildup.

Mushrooms don’t have skin, and water is easily lost to the atmosphere. For these reasons, mushrooms need an environment with high humidity to grow.

If humidity is too low and conditions are dry, you will see mushrooms dry up as the cells lose water. If humidity is too high, the excess water in the air prevents gas exchange, and, just as with too much water in the substrate, the mushroom will choke to death.

Ideal Temperature for Growing Mushrooms

While it will differ slightly among varieties, mushrooms prefer an environment with temperatures around 70 degrees Fahrenheit (21 degrees Celsius). Mycelia will form in temperatures ranging anywhere from 40 to 90 degrees Fahrenheit (5 to 32 degrees Celsius), and visible parts of the fruit tend to appear in temperatures between 50 and 70 degrees Fahrenheit (10 to 21 degrees Celsius).

Mushroom Nutrient Needs

In nature, mushrooms get their nutrients by feeding on dead plants. This is why many wild varieties, like morels, are found on the forest floor among dead leaves at the base of trees. You can also find mushrooms growing on trees, mulch, soil, dung, or compost, eating the decaying or dead matter from those substances.

Mushrooms feed on compounds found in plant cell walls such as cellulose, hemicellulose, and lignin, which provides most of the nutrients required to grow, but mushrooms also like to have:

  • Nitrogen (around 0.2 to 0.4 percent content in the substrate)
  • Minerals (such as magnesium and calcium)
  • Almost neutral pH levels (range of 4 to 7, depending on the mushroom)
  • 50 – 70 percent water content in the substrate

Nine Types of Growing Media for Mushrooms

Photo by Miriam Doerr

Mycelium will spread and fill the area of any containment you choose. You can grow mushrooms in a large, raised-bed garden outdoors or a small bucket or jar indoors—it is up to you. If you have limited space or live in an apartment with no yard, for example, then a small plastic tub on your countertop or a few zipped bags in a closet may be good options for you.

The more important thing to consider when growing mushrooms at home is the substrate.

Quite often, more than one substrate is mixed together to grow mushrooms to supply all the nutrients needed. There are many kinds of ready-made substrate mixtures you can purchase, or you can always create your own.

Different mushroom types may favor one substrate over another for the particular nutrients it provides, so again, a little research into the type of mushroom you wish to grow will help you in your decision. However, in general, you have a handful of common options to choose from that are proven efficient and readily available.

Sawdust or Wood Chips

Hardwood sawdust and wood chips are a common choice as wood is many mushrooms’ substrate of choice in nature.

In particular, sawdust pellets are great because the process of turning sawdust into pellets sterilizes it, so there’s no need to take on that step yourself. You can use these to grow nearly all types of mushrooms, but it is best for varieties that grow naturally on dead trees. Sawdust is also often used for inoculating logs.

Straw

Straw can be used to grow almost any kind of mushroom, but some may require another substrate to supplement nutrients to allow for better growth. Many oyster mushroom growers tend to favor this medium. Working with straw will be easier with smaller pieces cut roughly 3 to 4 inches (7 to 10 cms) long. Additionally, it will need to be pasteurized.

Coffee Grounds

Coffee grounds will almost always require a supplement for optimal mushroom growth, but varieties such as shiitake and oyster have been known to do pretty well in coffee grounds alone.

Coffee grounds, however, are typically used to supplement other substrates. After making coffee, spent grounds will remain sterilized for about a day, so you’ll need to re-sterilize them if they aren’t used within 24 hours.

Rye Grains

Rye grains are commonly used for creating mushroom spawn that is later used to inoculate the majority substrate. Many different kinds of mushroom spawn will grow on rye grain, and it is often found in many ready-made mixtures. Whether pre-mixed or a custom-blend, plan for the sterilization process if you go with this choice.

Manure

Manure is loved by many types of mushrooms, such as the button mushroom. Generally, supplemental growing media should be used for proper moisture control. Things like straw or coir (coconut husk fibers) make for good mix-ins.

Hardwood Logs

This is a popular choice that will be preferred by some mushroom varieties, but log inoculation requires some special tools to get the job done (we will discuss this in more detail later on). Hardwood logs perfectly mimic the natural environment of mushrooms. Popular choices include:

  • Alder
  • Aspen
  • Balsam
  • Beech
  • Birch
  • Elm
  • Maple
  • Oak
  • Polar
  • Willow

Woods that should be avoided include:

  • Black walnut
  • Black locust
  • Most evergreens

Coir with Vermiculite

While both these materials are commonly found as part of a ready-made substrate mixture, they can also be found individually. You can use one or both to supplement other substrates, but the two of these together make for a good manure substitute.

Cardboard

Cardboard works as a great substrate, plus it’s cheap. It also mixes well with coffee grounds for nutrient supplementation. This substrate works well when placed in layers, alternating with grain spawn (like a lasagna). Boil in hot water and cool before using.

Toilet Paper

Toilet paper is a fairly common substrate, particularly among beginners and for growing oyster mushrooms. In general, not much spawn will be needed, and anything from sawdust spawn, grain spawn, or oyster mushroom stem butts will work.

Step-by-Step Guide for Growing Mushrooms Indoors and Outdoors

Photo by Hirav Patel

Mushrooms can be grown indoors all-year-round using a basic growing method inside a plastic tub or even a plastic bag. The size of your containment is up to you. All you need to do is provide a dark, cool place for them to grow—a basement, crawl space, drawer, closet, or cabinet will all do the trick. As long as there is near darkness and you can control the humidity level, it’s good.

Outdoor growing methods include garden beds, log inoculation, and “the natural method,” which is simply mixing spawn with compost and allowing nature to take its course. Log inoculation is very popular, or you can place raised beds or damp straw to grow mushrooms in shady areas in your garden.

Growing outdoors will require you to be mindful of your local climate and choose a variety that will do well where you live. Mushrooms prefer humid and cool conditions, but some can grow in more arid climates—you’ll just need to water them more often.

As we’ve said, growing outdoors will take considerably longer than growing indoors (from six months to two years). However, once mushrooms do start growing, healthy colonies can continue growing for years.

Indoor Mushroom Growing Guides

Here are three ways you can grow mushrooms indoors.

Step-by-Step Guide for Growing Mushrooms Indoors Using Spawn

These are the materials you will need:

  • Sterilization/pasteurization items (such as bleach wipes, pressure cooker, water, etc.)
  • Plastic bins/bags/buckets, baking pan, or similar
  • Mushroom spawn
  • Growing substrate
  • Supplies for pasteurizing substrate, if applicable
  • Spray bottle filled with water
  • Heating pad (optional)
  • Damp towel (optional)

To grow mushrooms indoors using spawn, follow these steps:

  1. Ensure your growing container is clean and sterile. If using a substrate such as straw or sawdust, pasteurize before using.
  2. Put several handfuls of the substrate into your chosen container. Mix the mushroom spawn into the substrate and cover or close the container, allowing for some air exchange. Keep the mixture at a temperature of about 70 degrees Fahrenheit (21 degrees Celsius), or whatever is appropriate for your particular spawn. A heating pad works nicely if needed.
  3. In about two to four weeks, the spawn will become mycelium and take root in the substrate. When this happens, bring the temperature down to 55 to 60 degrees Fahrenheit (13 to 15 degrees Celsius), or as preferred by the mushroom variety. Cover the substrate and mycelium with an inch (2.5 cms) or so of potting soil, and spray with water until the mixture is damp. You can place a damp towel on top to help retain moisture.
  4. Continue to spray water on the soil when it gets dry to the touch. If kept moist and cool, mushrooms should grow in about three weeks. Once the cap has separated from the stem and has fully opened, your mushrooms are ready for harvest.

Watch this video for a quick demonstration of using grain spawn indoors with a log or toilet paper as the substrate:

Growing Mushrooms Using Ends from Store-Bought Mushrooms

This method is similar to the above, except that mushroom stems are taking the place of spawn. Typically, oyster mushrooms are best for this process. You may start in a small jar and later transfer to a larger bin or bucket, and a simple substrate such as cardboard can be used. 

Here’s an informational video that walks you through the essentials:

Kits for Growing Mushrooms Indoors

Kits are great for cultivating smaller amounts in controlled environments and allow you to change between favorites and grow more variety. Also, it’s a great way to cut a few corners. Here are a few we recommend (you can find them all on Amazon):

Outdoor Mushroom Growing Guides

Here are three ways you can grow mushrooms outdoors.

Step-by-Step Guide for Growing Mushrooms Outdoors in a Mushroom Bed

Here are the materials you will need:

  • Cardboard
  • Wood chips (avoid options that have been chemically treated)
  • Straw
  • Mushroom spawn
  • Raised bed or wood for sectioning off (optional)

Steps on how to grow an outdoor mushroom bed:

  1. You can choose to set up your mushroom bed however you wish, be it underneath trees or bushes or in a raised bed off to the side. Ideally, mushrooms should be grown somewhere there is ample shade, and they won’t dry out too easily. If the location you pick is an exposed area, consider topping the bed with shade cloth or netting to provide extra shade.
  2. Start by lining the bed with cardboard. Then, alternate layers of wood chips and mushrooms spawn, starting with a wood chip layer and topping with an even layer of spawn. Continue layering wood chips, then spawn, then wood chips, then spawn, until you’ve used up what you have. Aim for a total of three even layers within your designated space.
  3. Spread a thick layer of straw across the top the entire bed. Though straw is also a good substrate, the idea here is to act more like mulch would for plants. It will help to maintain moisture as well as provide some insulation and warmth in colder weather. Once you’ve set the straw, dampen the entire bed with water.
  4. Continue to provide water for the weeks and months that follow to keep the mushroom bed from drying out. Whether by rain or garden hose, the bed should be given a good soaking at least once a week. After two months, you should start to see mycelium growing, and by six months, mushrooms should appear.
  5. Harvest mushrooms before they grow too large: as caps grow, they will begin to disintegrate, and insects will start to crawl inside. Ensure the mushrooms that grow are true of your spawn because, while unlikely, a rogue wild variety can find its way in there. To keep the bed going, give it a fresh feeding with a new layer of wood chips every year. Mushrooms should continue to grow for years to come.

Growing Mushrooms Using Log Inoculation

Log inoculation is one of the oldest, first-ever methods of mushroom cultivation perfected for over a thousand years in Japan. It is one of the most popular ways to grow mushrooms outdoors. Cultivation is often slow with this method, but it sure does look spectacular!

This video shows you everything you need to know to do this properly:

Kits for Growing Mushrooms Outdoors

You can get outdoor mushroom log kits from a variety of vendors. We recommend checking out the outdoor mushroom log kits from NorthSpore as they have a lot of choices. Some other popular and trusted places include:

Already have a prepared log and just looking for spawn? No problem. Products like Shiitake Plug Spawn provide you with fast running mycelium on plugs ready for your log, complete with inoculation instructions.

How to Harvest Your Mushrooms

When mushrooms have developed to your liking, use a knife to harvest them, cutting as close to the substrate as you can. Pulling mushrooms is not recommended, as you will likely remove part of the mycelium block in doing so and compromise subsequent flushes. If you’ve done well, you may see up to three flushes of mushroom production from the same substrate.

Eight Common Reasons Mushrooms Fail to Grow and What You Can Do

  • Not enough moisture: Moisture and humidity levels are important and require your close attention when growing mushrooms at home. Conditions should be kept moist, so misting and watering must be done frequently.
  • Too much moisture: Moisture is good, but too much can lead to mold. Your project should not be allowed to sit in standing water. Good drainage is the key to a proper balance.
  • Not sterile enough: Foreign organisms can contaminate and kill your project before it even really begins. Wash your hands and properly sterilize all your materials and tools.
  • Lack of air exchange: While mushrooms don’t need a lot of oxygen, they do need some. If carbon dioxide levels are left to build up, it could lead to stunted, spindly stalks with no caps. Sealed containers should be opened at least once a day to allow for air exchange, and projects shouldn’t be left in places that lack fresh airflow.
  • Growing in the wrong environment: As is true for most things in nature, the environment matters. Some mushroom species prefer warm temperatures and will struggle in cooler weather. A wood-loving species, for instance, will not grow as well on straw. Research the mushrooms you wish to grow—particularly if you’re looking to grow outdoors—to make sure your local climate is appropriate.
  • Bad inoculum: Mushroom spores don’t stay viable forever, so it’s important to purchase them from a reputable supplier and ensure you’re getting a fresh product. When buying online, keep shipping times short. Most varieties should be able to hold for a few months under certain conditions.
  • Not understanding the mushroom life cycle: You don’t need to become a professional mycologist, but without a general understanding of the mushroom life cycle and the environmental requirements, growing mushrooms could be a tricky task. Do your research so that you can best care for your mushrooms.
  • Lack of patience: As we said before, growing mushrooms takes time. Mycelium can be slow to grow into the substrate, and it will take some time, ranging from a few weeks to years depending on the variety. Just be patient.

Closing Thoughts

Growing mushrooms at home is easy to do with the right know-how. Indoor methods can make for an enjoyable and satisfying project, and mushrooms grown outdoors make for a wonderful addition to any garden. By making informed decisions in your substrate and mushroom variety, you, too, can become a seasoned mushroom grower in no time!

Supriya

Hi! I'm Supriya. I'm a home cook, bulldog mom, spicy food lover, and founder of The Spicy Trio. I have been a home cook for about 15 years and have been growing plants for the past six years.

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