How to Grow Specialty Mushrooms in Your Backyard
Today’s guest post is from Fungi Fun Guy, Michael Judd, author of Edible Landscaping with a Permaculture Twist. Michael’s book is a unique how-to manual for the budding gardener and experienced green thumb alike, full of creative and easy-to-follow designs that guide you to having your yard and eating it, too.
Back Yard Fungi
I often hear, “My yard is so shady that I can’t grow anything.” To which I get my big cheesy grin going and say, “Oh yeah you can! Mushrooms love shade!” Growing mushrooms outdoors is much easier than you may think.
Primarily, I grow three types of mushrooms: shiitake, oyster, and wine cap. These types are easy to grow, tasty, and versatile. I grow shiitake and oyster mushrooms on logs, and the wine cap mushroom, also known as King Stropharia or Garden Giant, I grow on wood chips. All three of these have a wide temperature range for growing as long as there is moisture—make that moisture, moisture, moisture! If you retain nothing else from this project, simply remember: moisture = mushrooms.
Log Culture – The Nitty Gritty
Many types of trees can be used for growing edible mushrooms. In general, you should use hardwoods like maple, poplar, willow, birch, and beech, while avoiding species such as black locust, black walnut, and most evergreens. Our land here in Maryland is rich in tulip poplar and hard maple, perfect for oyster and shiitake, respectively. Oak is the king wood for shiitake, with its thick, protective bark and strong, long-lasting wood. A good oak log can produce beautiful shiitakes for up to eight years, whereas a softer wood like poplar may produce for only three to four years.
Now, you might be thinking, “How is cutting down trees to grow mushrooms ecological?” Our forests have lamentably been chopped down multiple times since the New World began, and the resulting regrowth is usually a cluster of crowded saplings. A practice of sustainable forestry is the thinning of small-diameter trees to allow the larger, more mature trees to grow and to let in more sunlight that helps regenerate the forest floor. These saplings are the perfect size for mushroom log cultivation.
Simply grabbing some old firewood off the pile to grow your mushrooms won’t work, since the wood already has its own funky fungi going on. Mushroom wood needs to be fresh and from healthy trees. I cut my wood at winter’s end before sap rise, which in Maryland is around the end of February/early March. Trees or branches approximately six inches in diameter are best. A larger diameter is fine if you have the brawn; however, smaller diameters are not recommended, as the wood will dry out too easily. Once downed, I mark and cut the logs at about 40 inches in length, which makes a manageable size to move around. I then leave the logs where they are, slightly lifted off the ground, or move them where it is moist, leaving them for about three weeks. This period allows the tree’s natural anti-fungal properties to die off and the temperature to warm up for inoculation in late March or early April.
Note: if you have healthy wood that was downed during the winter, it is usable as long as you inoculate in the early Spring.
Ninja Move: Put spore-inoculated bar oil from Fungi Perfecti in your chainsaw so that as you cut wood, you seed the stumps and surrounding debris. Throw some sawdust back on the stump to help keep in the moisture.
Fungi, the mushroom body, is made up of thread-like cells that weave together to make a network. When ready to fruit and release spores (seed), up pops the edible shoots we love so much. If you have ever kicked aside the leaf litter in a forest and seen the white webbing, then you’ve seen fungi. We call these threads “mycelium.”
For mushroom cultivation, we want specific fungi mycelium (i.e., shiitake and oyster strains). The mycelium growth is started on sawdust, straw, grain, or little wooden plugs. When inoculated with mycelium these mediums are called “spawn.” Think of them as kindling to get the mycelium going. For beginning ease, I suggest purchasing spawn with mycelium on them from one of the many fine mushroom supply outfits; ideally, one close to your weather range. I am a big fan of Field & Forest. Their claim is: “Proud to be part of this rotting world.” Their website and online catalog are a perfect package of how-to’s and materials for beginners.
There are numerous spawn options, but for small-scale use, I prefer the plug spawn. Plug spawn are little birch dowels that arrive covered in the mycelium variety you choose. These spawn will be inserted into the logs.
- A log roughly 6 inches in diameter by 40 inches long will take between 30-40 plug spawn. 250 plugs run about $20.
- There are shiitake and oyster varieties that fruit at different temperature ranges, offering extended harvest throughout the growing season (early spring to late fall).
- Spawn can be ordered a month or so in advance and kept refrigerated.
- You can also collect your own spores from local fruiting varieties (which has the benefit of being a more resilient strain).
- I highly recommend reading Mycelium Running: How Mushrooms Can Help Save the World by Paul Stamets. I consider this to be the bible on mushroom cultivation and use.
Setting Up the “Shroom Zone”
Before the big bucks start to roll in from your mushroom sales, a bare bones work area is needed. Come late March/early April, I set up my super low-tech inoculation area outside the garage. It’s comprised of a few straw bales laying flat, a strong electric drill, a hammer, an old camping stove, and a nasty old fondue pot.
• Hardwood logs (6 inches by 40 inches)
• 5/16″ wood drill bit
• Electric drill
• Straw bales as work bench or other low surface to work on
• Camping stove or other outdoor heating source
• Wax (cheese or bees)
• A small bristle brush, small paint brush, or wax dauber
• Good beer
• Optional: metal label tags
Once you have your shroom zone set up and first brew poured, it’s time to arm yourself with a drill. The logs are going to be drilled in a diamond pattern for the plug spawn. Start the first row two inches from the log’s end. Space the holes every six inches. The depth of the hole is important. Ideally, the plug will be inserted to a depth just below the bark, almost flush, but not sticking out, about 1 inch deep. Field & Forest sell ninja drill bits that have stoppers on them for the correct depth, but I have used a piece of tape or a pen mark on the bit to eyeball the depth. It’s good to drill a few holes and check the depths by tapping in the spawn to see how it fits. Soon, you’ll get the feel for it. Use caution not to drill too deep, as that leaves a dry air pocket.
Once you have your first row done, rotate the log two inches and begin the next row, starting between the first two holes of the previous row, approximately five inches down. Continue rotating the log two inches for every new row and offsetting the holes to create a diamond pattern. The inches here are approximate, so don’t get worked up, just pull on the brew for balance. Drilling this many holes is a bit overkill, but it’s necessary to make sure that our chosen fungi is the one that colonizes and out-competes any other funky airborne fungi.
Whacking in spawn plugs is fun. Those skills you built up playing the fair game Whack a Mole are about to pay off. As fun as whacking stuff may be, we need to be careful not to damage the bark. The bark on your log is the skin that keeps the moisture in, so handle it gently. Oaks, with their thick bar, are favored in this process; poplars, with thin and brittle bark, not so much. Some folks recommend using rubber mallets, but I find workshop participants tossing them aside in favor of the metal hammers. Now, armed with your hammer and a bag of spawn, let’s get to it. Keep in mind that the bag of spawn is sensitive to drying out and should be protected from sun and wind while working.
About the time I’m ready to start whacking in spawn, I set up my hybrid wax-melting station. This station uses an old Coleman two-burner propane gas stove. I set this up about 20 feet from the drilling and whacking stations, as the wax smoke can get thick and the wax will inevitably drip. I’ve seen set-ups in the garage with a plug-in burner and tarp underfoot, but that somehow loses the outdoor mystique. Both approaches work. For a pot, I use an old fondue pot, but really any pot will do. Some more legit folks might recommend using a double boiler and putting water in the bottom of the first pot or even just placing a metal bowl in a pot with water in the bottom as a makeshift double boiler.
I use a cheese wax that I get in big chunks cheaply from Field & Forest, and it seems to last forever. Start off with a fist-sized chunk. I crank the heat to medium high and watch until the wax melts clear and starts to fine bubble. Then, turn the heat to low, around 300 degrees. You want the wax to be as hot as possible without catching on fire. I judge the heat by the smoke; a thin smoke is good, while a thick one is getting close to the flash point. Often during workshops, where I have a small army of first-time drillers and whackers, I forget to turn the wax down and it catches on fire. It’s no huge blaze, but you cannot salvage the wax once it’s caught fire. I carefully take it off the burner, dump it on the gravel drive, and start again. The flash point is easier to control with a double boiler set up. The trick is to have the wax as hot as possible to ensure a good seal that traps moisture and keeps critters out; otherwise, the wax can dry and peel off. Once your wax is hot, use a small bristle brush, a steel baster, or wax daubers (which are a dollar a pop from Field & Forest) to dab the wax over each spawn.
If you have, or plan to have, multiple types of mushrooms, it is a good idea to label the logs with aluminum tags nailed into the log’s end. Put the type, variety, and date. It will help to track what does well, to make recommendations to others and be sure you are harvesting the right fungi.
A Shady Place for Some Shady Characters
The next stage in the fungi journey is one of the most critical: the spawn run. This is when the mycelium jumps off the spawn into the log and begins to colonize it. This can take anywhere from six to eighteen months. Be patient and have faith. Place the logs flat during the spawn run, just off the ground an inch or two. Moisture during this time is key. The logs want to be placed in a shady place that imitates a forest setting, out of the wind, and, ideally, close to the house and watering source. If you have a naturally moist, shady area around your house, that is a good spot. My new favorite place to stash logs is under the deck, where water falls through and the house blocks the wind. The fungi love it! Another good spot is underneath evergreens that are porous and allow enough water to fall through. You can create your own shade with a 60-80 percent shade cloth draped over straw bales with logs laid in between.
Keep your logs moist; water like your garden. If there has been no rain, they need the equivalent of about one inch of water a week. You can either hose and the area around them down once a week, or set up a sprinkler and run it for 15-20 minutes. Once the logs fruit, lean them up to view and easily harvest the mushrooms.
Harvest & Use
When the logs fruit, usually after a warm spring or fall rain, simply cut the mushrooms off at the base, being careful to not pull off chunks of the bark. Then, the sky’s the limit for enjoying and preserving them. You will be amazed at the abundance a log produces at once. If you can get past sautéing them in butter and garlic or making creamy mushroom soup, then they are easy to dry and store. My personal favorite preservation is shiitake vodka! But for you teetotalers, a mushroom-infused olive oil with peppercorns and hot peppers is a tasty treat and great gift.
A Word About Mushroom Safety
You may be wondering if is safe to eat any ol’ mushroom that grows out of the log. The answer is an emphatic “Hell No!!” If your spawn variety has not successfully run and colonized the log, it’s possible that another airborne fungi has set up shop. Only harvest the type that you inoculated the log with and have a picture of what that is. If you inoculate a shiitake, only harvest a shiitake. Oysters and shiitake are easy to identify. The beauty of growing your own mushrooms versus hunting for them is that you know exactly what is supposed to pop out.
Edible Landscaping with a Permaculture Twist is a how-to manual for the budding gardener and experienced green thumb alike, full of creative and easy-to-follow designs that guide you to having your yard and eating it, too. With the help of more than 200 beautiful color photos and drawings, permaculture designer and avid grower Michael Judd takes the reader on a step-by-step process to transform a sea of grass into a flourishing edible landscape that pleases the eye as well as the taste buds. With personality and humor, he translates the complexities of permaculture design into simple self-build projects, providing full details on the evolving design process, material identification, and costs. Chapters cover:
- Herb Spirals
- Food Forests
- Raised-Bed Gardens
- Earthen Ovens
- Uncommon Fruits
- Outdoor Mushroom Cultivation, and more . .
Distributed by Chelsea Green. For sale at ecologiadesign.com
Reprinted with permission from Edible Landscaping with a Permaculture Twist by Michael Judd © 2013. Published by Ecologia. Photography courtesy of Ecologia.