A Year of Mushroom Cultivation
I’ve always loved gourmet mushrooms as a delicious, nutritious food. When I became a vegetarian in 2003, I began to lean on mushrooms as a frequent main dish. Their rich textures and umami flavors season recipes and provide the substance and structure that often feels lacking when meat is removed from a meal. When properly cooked, they’re easily digestible and provide protein, micro-nutrients, and many health benefits. I tried inoculating some logs during my early days of farming, but it was a total failure. I had some reasonable success inoculating garden mulch with king stropharia, but I soon found that those mushrooms weren’t my favorite to eat, and I had trouble keeping up with the kind of mulch that they prefer. Despite my love for eating mushrooms, I swore I would never try to grow them in any kind of sterile environment. I’m a pro-microbe person. I never want to work in a sterile lab, I never want to own bottles of bleach, and I don’t want to lose all my free time to standing in the kitchen babysitting a pressure cooker. I like my food fresh from the ground or wild fermented.
Meanwhile, as my chickens aged, stopped laying, and eventually passed on, I found myself searching for a new way to fill some of the gaps they left behind in my farm ecosystem. My most dire needs were: a home grown source of kind protein with byproducts that would help build fertile topsoil in the gardens. I wasn’t committed to continuing with livestock, and I was open to new possibilities. So when, at the Indiana Small Farms Conference a couple years ago, I attended a presentation in which a farmer shared photos of a huge beautiful productive garden built entirely out of spent mushroom substrate blocks, my eyes opened wide. These urban farmers were purchasing pre-colonized mushroom grow blocks from a mycologist, fruiting them in a high tunnel, plopping the spent substrate blocks on top of their garden, and planting directly into them. They weren’t doing their own sterilization. Mushrooms weren’t their only crop. Their scale was similar to mine, and it finally seemed like this could be a viable option for my farm too. I wanted the mushrooms, and I needed the compost.
Spring Forward : Getting Started as a Beginning Gourmet Mushroom Grower
I ordered some equipment online. I bought a sealed grow tent, similar to a mini greenhouse with shelves inside, a fan, and a humidifier. I initiated a relationship with a local mycologist, and I dove in. There’s a lot more to it than opening the bags. I’ve made many mistakes over the past year, but I’ve learned some useful lessons as well. I am the kind of person who needs to try something before I can fully understand it, so the only real way for me to learn was to begin.
As a result of my experimental, hands-on learning style, I find the boundaries of things. I push them past their expected limits. And I find out what really happens when things are done in unconventional ways. As a farmer, my goal is not to get the highest yields from my endeavors. Instead, I’m seeking a balance between minimal inputs, harmony with the environment and the ecosystem, kindness, and an acceptable yield level. I want to know what can I harvest while having a positive impact on my surroundings.
Obviously, single-use plastic bags are not my long-term goal. However, it was the only option that seemed accessible to me as a beginner. I’m already moving past this stage and finding more sustainable solutions.
I’m not interested in building a new climate-controlled structure for this endeavor, nor did I want to grow mushrooms inside my house. As a compromise, I am growing my mushrooms on a covered screened porch. The outdoor temperatures are buffered, but not eliminated. This is a pretty unusual thing to do, it turns out. It presented some unexpected challenges, but I’ve had significant success as well.
Summer proved to be an even bigger challenge than winter. Most mushroom species are happiest between 50-75 degrees F. Indiana summers regularly settle into the 90s. However, spring weather is for mushrooms, and they flourished in their season.
Summer Culture : Keeping Mushrooms Cool During The Hot Months
I lost a number of my mushroom blocks to summer. When you combine heat over 80 degrees with the high humidity that mushrooms prefer, you’re more likely to grow mold than mushrooms. I composted the spoiled blocks, cleaned and disinfected the grow space, and re-ordered. By this time, my relationship with the local mycologist had fizzled, and I found myself searching online for a larger mycology company that could offer free shipping from not-too-far away. I tried one from Illinois, and the results were good. I tried different mushroom species. Some did much better than others in the heat. Pink Oyster has displayed the best heat tolerance in my trials so far. Blue Oyster also produces well in summer heat. Lions Mane has lower production in general than the oysters, but it also survived the summer and produced some. Shiitake produced a little, but it’s really more of a cool weather mushroom. Pioppino, King Blue, Black King, and King Trumpet are not worth trying again in summer heat. Reishi did well in the summer, but it’s more of a medicinal mushroom than a food. I did not try Golden Oyster, which is an invasive species that causes damage to local forest ecosystems. If this mushroom is not native to where you live, please don’t grow it, as you could introduce it via spore spread.
I made some adjustments to my growing setup. The first thing I tried was adding a personal-sized evaporative cooling machine to the top shelf of my growing tent. I placed the small unit in front of a large ice block right before the hottest part of the day, and let it blow cool air through the afternoon. I found this lowered the temperature inside the tent by about 8 degrees, and it also replaced the humidifier. This was a little labor intensive, but not too electricity-intensive, and it was cheap, since I found the cooling unit second hand for $5.
As summer grew hotter and hotter, I found the mold creeping back in. I cleaned and sanitized everything again, replaced all my blocks, and tried something a little simpler. I opened the grow tent, turned off the fan and humidifier, and just used it as a shelf. Though the temperature was still hot, the humidity was lower, and I found that contamination was much less of an issue. I did have to put more time into misting the mushroom blocks to keep them hydrated, but it really wasn’t too difficult. Interestingly, the blue oysters grew white. The pink oysters grew pale. The lions mane got a little yellow around the edges. But they all still tasted delicious, were mold-free, and produced decently, if not abundantly.
In hot weather, oyster mushrooms go from pin to harvest size in a day. You have to check them and be ready to harvest morning, noon, and night, or they will pass their peak and drop spores everywhere. This is to be avoided at almost all costs, as the mushrooms will not be as good, will not keep as long, and the cleanup work will be extensive.
Winter Culture : Growing Mushrooms in an Unheated Greenhouse
Autumn was a joy. I sealed up the tent again, resumed using the automated humidifier and fan, and filled the chamber with some fun new varieties like Maitake and Chestnut, and lots of the delicious King Blues and Shiitakes that summer had restricted. Autumn growing was pretty much trouble-free. As we descended into winter, my greenhouse was finally complete. It’s unheated, but it’s built on the south side of my brick house, and it extended the growing season nicely. I moved my mushroom blocks into a small seed-starting greenhouse inside of the main greenhouse. I filled it with a combination of seedling flats and mushroom blocks. This produced very well. The mushrooms breathe oxygen, like we do, and exhale carbon dioxide for plants to breathe. Both produced better when grown side-by-side. The greenhouse-within-a-greenhouse system generated significant extra warmth. On sunny days, I had to remember to go out and open the zipper on the inner mini-greenhouse, or it would easily exceed 90 degrees. The humidity from the well-watered plants was enough to keep the mushrooms happy without much misting or a humidifier.
Shiitake, Blue Oyster, and King Blue continued producing through much of winter. I was providing them to my CSA members most weeks through January 19. Yields were definitely reduced and more sporadic in the cold weather, since the fruiting process significantly slowed, but it didn’t stop until winter got really frigid. Shiitake yielded the least, but stayed in the game the longest, tolerating the coldest temperatures with no damage to the fruiting bodies.
One thing I’ll work on improving for the future is timing. Having new, seasonally appropriate fruiting blocks in the pipeline ready to mature in time for each new season would increase my yield and the harvest season. I didn’t want to invest in new blocks during the winter, since I didn’t know which ones would be viable, or when winter would kill them. Instead, I was re-fruiting older blocks. This carries less financial risk, but also reduces the potential for harvest. Planning for seasons in advance is a skill that I believe will greatly increase my yields. For example, Pink Oyster mycelium dies during a light frost, since it’s a tropical mushroom. They’re not worth any space in the winter growing setup. They won’t come back in the spring, like some other species will. So think about how much calendar time you can get out of a pink oyster fruiting block, and count backwards from your first frost date. Don’t start any pink oyster later than when you can reasonably expect to get your full value out of it. I also never got second fruitings from my chestnut and maitake fruiting blocks, but I’m not sure if that was my fault or if they aren’t suited to survive winter. More experiments are needed. This year as the summer heat wanes, I’ll be thinking ahead about fall and winter mushrooms, and halting any new pink oyster development in August. I’ll try to have some King Blue, Blue Oyster, Shiitake, and Lions Mane colonizing indoors during the worst of winter, so they’ll be ready to fruit in the greenhouse by mid-February after the coldest nights have passed.
Growing Greener : Enhancing Profitability and Eco-Friendliness in Mushroom Cultivation
I have not yet made a profit directly from my mushroom growing endeavors, though I have grown and sold a lot of mushrooms, and they have brought many new subscribers to my CSA. This is not very surprising. Mistakes are expensive and beginners make lots of them. I find that it usually takes a couple years to get good enough at a new skill to become profitable at it. I believe I’m on the right track. My yields are constantly improving, I’m figuring out tons of workarounds, and my customer base has been expanding at a much greater rate since I began offering mushrooms as a farm product. There’s a huge market for fresh, local gourmet mushrooms, and I’m confident that this is a skill worth developing. I’ve gained enough proficiency with the fruiting process now to begin acquiring other skills and becoming more self-reliant throughout the whole growing process.
I’ve been learning how to clone cultures, how to make my own liquid nutrient broths, how to colonize glass jars of grains, and how to make my own fruiting substrates for growing in reusable containers. These techniques require some extra work, but I think by batching and streamlining my processes, I’ll be able to handle it. I’ve also located some pre-sterilized grain jars and substrates that can be purchased and inoculated at home during my busiest times. I already own most of the expensive supplies I need for this, like a pressure canner and an outdoor burner. I’ve found ways to do it without any nasty chemicals. Heat or alcohol can solve most problems. Doing more of the work myself will significantly lower my input costs, and it will reduce or eliminate single use plastics from my grow.
Timing is another factor in my decision to take greater control over the whole growing process. It has proved to be impossible to source pre-inoculated grow bags with the right staggered timing. I might order a blue oyster growing kit on May 1, and then another on May 20, and they might come from the same exact batch. That means they were inoculated on the same day, and will mature and fruit right around the same time. That’s not what I want. I want to harvest a steady, continuous stream of mushrooms for my weekly deliveries. To make this happen, it seems I have to do it myself.
The shipping process causes additional problems. The heat and motion of transit often shocks the blocks of mycelium to fruit prematurely. If they fruit before the growing media is fully colonized, then the chances of getting a second fruiting from that block are greatly reduced, because any uncolonized media is at significant risk of contamination. When they start fruiting, I’ve been told to go ahead and open the bag even if it’s not fully colonized. I’m currently running a few trials to see what might happen if I don’t open the bag early, because early opening has been a significant cause of lost profits and reduced yields to date. But another way I think I can get around this problem is by colonizing the substrate myself and avoiding the transportation shock that seems to trigger premature fruiting in the first place.
The spent mushroom substrate blocks from my year of mushroom production have covered about a 4×10 section of garden so far, at about 4 inches deep. I’m going to grow potatoes in that bed this summer. I’m hoping that as I hill up the potatoes with generous quantities of straw, the mycelium from the spent mushroom blocks may colonize the straw and give me some bonus harvests. In any case, I think my potatoes are going to love that nutrient-rich growing environment.
Growing in Balance : The Power of Small Scale Diversification
Based on my experience and on many conversations with other mushroom growers over the years, I’ve come to believe that small scale gourmet mushroom production is the most enjoyable and sustainable way to produce edible mushrooms. At this scale, the materials I need are minimal, and the effort I invest is reasonable and enjoyable. With a little more experience, I can increase sustainability by moving away from single-use plastic, using more local ingredients, and maybe even producing some of my own straw and grain for inoculation. The waste products from growing mushrooms are highly valuable in my garden. Even the C02 that the mushrooms exhale is a valuable asset in the greenhouse all winter. Large scale greenhouse growers often purchase a machine called a C02 Generator, which consumes fossil-fuel propane and produces copious amounts of C02 (a greenhouse gas) as its primary goal, to boost plant productivity. The fact that such a machine exists hurts my heart. Skip the propane. Grow mushrooms and plants together. You can produce greater yields of both while maintaining balance naturally.
When we try to produce one thing in isolation, or we try to scale up beyond our boundaries of enjoyment, financial comfort, and interconnected relationship, we spin out of balance. I’ve known numerous growers who burned out or over-leveraged by scaling up too much too fast. Farming in general is labor-intensive, risk-inherent work. My strategy has always been to never take on debt for my farm. If I don’t have the cash available to invest in a new project, I don’t move forward with it until I do. That way, if I lose money, I don’t lose my farm, and I don’t lose my freedom to spend my time farming. Therefore, there will be no new building to house mushrooms year-round on this farm. I also don’t scale quickly. I dip my toe in, run lots of tests, and expand gradually in tandem with my increasing skill level. This runs contrary to most of the business advice I have received. However, I’m pretty sure that farming is the exception. Expanding in this slow, measured way allows me to make small mistakes instead of big ones. It allows me to produce most of the materials I need for expansion. For example, I can save my own seeds. I can divide my own plants. I can make a large percentage of my own compost. I can diversify my tasks in ways that reduce fatigue, stress, and injury risk and increase learning and enjoyment and connection. This is the mode of operation that feels sustainable to me, and it has served me well so far. It’s also very rooted in the teachings of permaculture. Permaculture teaches us to start small, to build connections, and to diversify in ways that build self-sustaining stable systems. I’m grateful for all that has brought me to where I am now, and I look forward to all that is ahead. Farming is the hardest job I’ve ever had, but it’s also the most rewarding.