Mushrooms are an increasingly popular crop worldwide and in the United States. Each year, farmers harvest approximately 900 million pounds of mushroom crops that are worth approximately $1 billion and this number is on the rise. It’s no wonder given the multiple advantages of mushrooms – not only do they have incredible health benefits, but they are also great for the economy and extremely versatile.
One who knows a lot about mushrooms is mycologist and author Paul Stamets, founder of mushroom cultivation and research company Fungi Perfecti.
Fungi Perfecti is “a family-owned, environmentally friendly company specializing in using mushrooms to improve the health of the planet and its people.” Through their website you can buy products derived from mushrooms, as well as mushroom spores and mushroom growing kits.
Paul has been a dedicated mycologist for over twenty years. Over this time, he has discovered and coauthored four new species of mushrooms, and pioneered countless techniques in the field of edible and medicinal mushroom cultivation. You might recognize him from his TED talk on 6 ways mushrooms can save the world. I recommend you watch it if you want to know more about his work.
He has written five books on mushroom cultivation, use and identification and his books Growing Gourmet and Medicinal Mushrooms and The Mushroom Cultivator (coauthor) have long been hailed as the definitive texts of mushroom cultivation. His book Mycelium Running: How Mushrooms Can Help Save the World is our favorite here at the office.
Paul really thinks that mushrooms can help save the world and restore our ecosystems. Is he crazy? Not at all.
In fact, the more research that goes into mushrooms the more amazing abilities are discovered. Not only can mushrooms fill empty bellies and help heal various health conditions, discoveries have also been made of mushrooms that can break down oil and even plastic, and fungi webs in the soil that help regenerate the ecosystem.
So yes, it looks like mushrooms really can help save the world, and it’s people like Paul we have to thank for this insight. Now let’s take a closer look at the benefits of eating mushrooms, and then we’ll dive into the practical questions of how to grow mushrooms.
Why farm mushrooms?
From a purely economic standpoint, the beauty of farming mushrooms is that unlike many crops, mushrooms can be grow all year round – this is advantageous for farmers, because they can count on a more consistent revenue stream.
But consumers are increasingly turning to mushrooms for their health benefits. Mushrooms have been revered for their superior nutritional value for millennia. As early as ancient Egyptian times, mushrooms were considered to be the “plant of immortality” and were fed to pharaohs and royalty exclusively for this reason. Early Romans similarly called mushrooms the “food for the gods.” And in South America, indigenous tribes referred to mushrooms as “meat,” because it was thought the nutritional properties were commensurate with meat.
But today, we know the health benefits of mushrooms are proven. The Federation of American Societies for Experimental Biology (FASEB) found that people who regularly incorporate mushrooms into their diet have a better overall diet quality that those who do not. And FASEB reports other unique health benefits too. First, FASEB found that substituting read meat with one cup of white button mushrooms per day can assist with weight loss. And mushrooms are a great source of vitamin D – in fact, consuming dried mushroom extract was found to be as effective as taking vitamin D supplements directly. And people who consume mushrooms were found to have a boost in their immune function due to the long chain polysaccharides found in mushrooms. Shiitake mushrooms in particular were found to induce positive effects on immunity and can even help ward off salmonella.
Other studies have shown that mushrooms have antidepressant properties and can do things like increase blood flow, stabilize cholesterol levels, and even treat some forms of Hepatitis. Many athletic trainers use mushrooms to increase ATP production in muscles, which helps athletes enhance their performance by improving their strength and endurance.
Mushrooms serve many other purposes beyond simply being a food source, too. For one, they are natural composters. For example, to grow mushrooms you actually recycle decaying plant matter and convert it into rich soil. As such, many farmers will grow mushrooms as a way to create fertile soil, ripe for planting other crops at a later date.
Another unique feature of mushrooms is that they absorb anything in which they’re grown in. If mushrooms are grown in contaminated soils, they take on this composition, including things like heavy metals and water pollutants. For this reason, mushrooms are an ideal crop to be grown organically and consumers are showing increased demand for this.
Mushrooms are also commonly used as dyes. When boiled, they release strong, vibrant colors that are used to dye things like textiles and cotton.
How to farm mushrooms
The mushroom farming industry in the United States is currently comprised of less than 300 farmers. But increasingly, new “micro-farmers” are getting into the business of mushroom as it’s an ideal crop for small operations. The reason is mushrooms are incredibly easy to grow and maintain once the operation is up and running. And the costs are relatively low compared to other crops.
The first thing to know about growing mushroom is that unlike most crops, they do not start as seeds. Mushrooms actually start from spores released by mature mushrooms – one mushroom can release as many as 16 billion spores. What is great about mushrooms is that they often don’t require much maintenance and spread freely with little or no intervention at all.
Mushrooms come in many shapes and sizes, so it’s important for farmers to carefully consider which variety is most suitable to them. For instance, are you farming mushrooms for their value as a food source or medicinal properties?
Oyster mushrooms are a good starter mushroom, because they’re easy to grow, thriving in almost any conditions. They also sell at good prices, typically $3 per pound, (the average mushroom sells more often for $1.25 per pound) making them a highly profitable and reliable choice. But there are many other good mushroom options as well so it’s important to spend a lot of time researching which is best for you.
Another major consideration when choosing the mushroom species to grow is your climate, particularly if you’re growing outdoors. Mushrooms like moist climates so really arid climates can dry out the mycelium in the mushrooms. But too much moisture can create mold and rot.
When selecting a mushroom is also important to consider what season you’d like it to be grown and harvested in. Oysters, Morels and Turkey Tails grow best in the spring. Early summer mushrooms include Shiitake, Elm Oysters, Reishi, and Garden Giants and late summer mushrooms include Button, Chanterelles, Maitake, Pioppino and Black Trumpets. Cold weather species include Enokitake and Shaggy Mane.
Once the mushroom species is selected, the next step is to choose what type of organic medium to grow the crop in. Typically, farmers choose between things like compost, straw, sawdust or wood chips, coffee grounds and logs. Whatever you select may depend on what is most accessible to you, but other factors should be considered as well, since some species work best with certain medium.
Compost and straw are both cheap and readily available. Similarly, coffee grounds can be easy to come by from a local coffee shop interested in being sustainable. Sawdust and wood chips are as well, but their size can present problems – too fine and they restrict air flow, too large and this causes to much air penetration; for this reason, farmers often combine saw dust and larger wood chips together. Finally, logs make a great medium for growing mushrooms, but they can be more difficult to get access to and mushrooms make take a longer time to flourish in this substrate.
If this is your first time growing mushrooms, the next step is to purchase a mushroom starter or spawn. Many online vendors sell mushroom starters or you can purchase from a local farm or university. This will only be a one-time thing, since once you have your mushroom farm up and running, you will have the starter spores from there on out. You can reduce costs by creating your own spawn too; however, keep in mind that spawn creation is a very time intensive process that requires a lot of vigilance. The main challenge with creating your own spawn is creating a perfectly sterile environment that is free of contaminants that could potentially threaten the mushroom crop.
In order to flourish, mushrooms require an extremely clean environment. As such, farmers must sterilize or pasteurize the substrate prior to cultivating mushrooms. This eliminates bacteria that can threaten the mushroom crop, including things like mold, which thrive in a similar environment as mushrooms. When considering whether to sterilize or pasteurize, keep in mind that pasteurization is most suitable when mushrooms are grown in an open area. To pasteurize, simply place the substrate into water that has been heated to one hundred sixty to one hundred eighty degrees Fahrenheit; temperatures that fall outside of this range will either not properly kill bad bacteria (if it’s too low) or could threaten the good bacteria (if it’s too high). Sterilization is preferable if the crop will be grown in a closed environment; it involves simply heating the substrate to a temperature above one hundred eighty degrees Fahrenheit for an extended period of time.
One the environment has been properly cleaned, the next step is inoculation. Inoculation is the process of mixing the mushroom spawn into the sterilized substrate; this is typically done within a container within which the crop will be incubated.
The incubation period is critical, because it greatly influences the health of the mushroom crop later on. The most important thing to get right during the incubation stage is air flow. Mushrooms breathe oxygen and give off carbon dioxide – too little oxygen can compromise the growth of mushrooms.
Another important consideration is how much sunlight the mushrooms will receive during incubation – indirect sunlight is ideal, since too much direct light can dry out mushrooms that tend to like a moister environment.
Maintaining the right temperature is also key to the mushroom crop’s success. An optimal incubation temperature is between sixty five and sixty eight degrees Fahrenheit for most mushrooms, although oyster mushrooms have a wider range, growing anywhere between fifty five to seventy four degrees Fahrenheit.
Finally, it’s important to maintain moisture within the composition. Before the mushrooms have bloomed, it’s advised to mist the substrate at least once per day. Once the mushrooms start to bloom increase mists to up to three times per day.
Make sure you do not add excessive amounts to the incubation beds, as standing water can result in mold or rot, which could compromise your crop.
Mushrooms should start blooming within a few weeks. The good news is that after the incubation phase is complete, mushrooms are very easy to care for, particularly because they are “self-selecting.” Self-selecting simply means that they launch multiple stalks and only nourish the ones that are the fastest growing – i.e. the best performers. This helps ensure your crops yield optimal blooms. It’s important that farmers do not attempt to harvest these failing stalks – they are not edible and therefore should be thrown out.
To harvest, simply twist the mushroom caps and part of the stalk. Once a stalk has been harvested, the remaining part will rot. The bloom should rebound very quickly, as mushrooms grow fast and plentiful.
The Business of Mushrooms
As previously mentioned, the costs to start a mushroom farm are low. To get started, farmers only need to purchase spawn and a few pieces of equipment. By some estimates, starting a mushroom crop takes as little as $20. Once the crop is developed, farmers can use existing mushrooms to expand their spores. As such the return on investment can be huge.
Oyster mushrooms are one of the more lucrative species, fetching around $10-$15 in some parts of the United States. And even a small crop of about two pounds of spawn should yield farmers about $200 per month or more year round. But this is the low end of potential income. It all depends on the crop size, mushroom species and buyer.
Since nearly all mushroom sales across the country are fresh from the farm, farmers aren’t required to have their crops inspected or follow burdensome regulations. Unless you’re processing the mushrooms, regulations are minimal or non-existent. One exception is if farmers want to get their crops certified as organic.
For this reason, selling mushrooms locally within the community is the best way to get smaller operations to market. Many local restaurants will purchase fresh mushrooms direct from farmers or tapping into local grocers or farmer’s markets is another good option.
Many mushroom farmers also sell their leftover substrate to local farmers, since mushroom substrate is an incredibly rich and potent fertilizer.