Growing edible mushrooms in Butte County’s hot and dry climate
On a recent hot September Sunday, Carl Rosato began relocating about 200 logs inoculated with shiitake-mushroom mycelium, the thread-like, branching growth of mushrooms often found below ground or in a rotting log. The logs have been providing mushrooms to Rosato for about four years at http://woodleaffarm.com/, outside of Oroville.
“I’m moving them from under a big live oak to under my bamboo where I think [the bamboo] can take the excess water,” Rosato said in a recent phone interview. “The oak tree, I think, is being harmed by too much water.”
Rosato is well known in Northern California for his massively popular peaches, along with the pears, apples, cherries and other fruit he grows on 26 acres of certified-organic orchards—the ninth-oldest organic farm in all of California, he says. But, come early fall, some of his customers at farmers’ markets at such locations as the Ferry Plaza in San Francisco and downtown Berkeley begin to ask: Where are the mushrooms?
“I’m growing them primarily so that I’ve got them in my diet, but as I’ve got excess—which I’ll have in the fall when I’m still marketing my pears—I’ll sell them for good money at the markets,” Rosato said.
He regularly sells out of the mushrooms he has brought to market for the past three years. Rosato cites their high protein level—around 18 percent of their dry weight—and their anti-cancer properties as to why he grows them.
But growing them can be challenging. “It’s a whole process of watching your logs and getting in tune with your logs,” which takes time and patience, he said. “It’s not for everybody—it’s not so easy.”
The hot, dry Sacramento Valley is not ideal for outdoor mushroom cultivation, noted Sherri Scott, owner of GRUB Grown Nursery and an amateur mycologist. She’s attempted to grow edible mushrooms at the GRUB Cooperative on Dayton Road but has yet to be successful, although she was able to grow edible mushrooms in the Bay Area before coming to Chico. “A lot of the species like the 70-degree range. … In this area, it’s hard to moderate the temperatures. It’s a little more challenging because of our heat and the dryness,” she said.
Scott lists a number of edible varieties popular for home growers, including maitakes, the medicinal mushroom reishi, Garden Giant (or King Stropharia), and the Hypsizygus ulmarius garden (or “HUG”) mushroom—also called the white-elm mushroom. The latter two, unlike shiitakes, are propagated in the garden among vegetables, often in a bed of straw, which doubles as garden mulch.
Oyster mushrooms, another variety of mushroom that is “one of the easiest ones to grow,” can be cultivated in a number of ways, including in used coffee grounds, Scott said. She also points to mushroom kits—consisting of a box that comes with an inoculated bag of a medium, often sawdust or wood chips, that requires only regular water to begin a “flush” of mushrooms in just a few weeks—as the easiest way to grow at home.
Scott recommends Marysville-based www.mushroomadventures.com as a good source for kits. The company, which sells its mushrooms at the Chico Saturday Farmers’ Market, is well known online for its popular kits to grow portabella, white button and oyster mushrooms.
Scott will be co-hosting an Edible Mushroom Propagation workshop on Sept. 29 through Perma-fun-k, a nonprofit dedicated to permaculture and regenerative-agriculture education, as part of its fall series of permaculture classes at GRUB. It will cover the basics on home mushroom propagation, including a chance for participants to inoculate some logs.
To grow shiitake mushrooms, a grower must first purchase “plug spawn”—small wooden dowels that are colonized with mushroom mycelium. The plugs are driven into holes drilled into a hardwood log. Rosato recommends “live and fresh” oak wood as the best medium for shiitakes. “I’ve tried pecan and peach, but … I’ve got live and white oak around here … and that’s what they like the most, anyway,” he said.
Rosato strongly encourages mushroom propagators to ensure their removal of wood from a forest for growing mushrooms is not detrimental to the hillside ecosystems. “If a branch breaks and you cut it, or you need to prune it anyway, then that’s the wood that you use that’s live and fresh,” instead of indiscriminately cutting trees or clear-cutting, which can lead to major ecosystem upsets such as erosion and habitat loss.
He uses 4- to 7-inch-wide branches from his farm that need to be trimmed anyway, cut into 3-foot segments. After a few weeks of resting, the wood is drilled and inoculated with plugs, and the plug holes are sealed with wax. After that, it’s just regular watering—Rosato waters twice a day for 15 minutes to ensure the bark remains evenly moist. “[The time from when] you plug them until you get the first mushroom is about a year,” he noted.
Before Rosato’s logs are moved to their new location in the bamboo, he will soak them in water for 24 hours, to encourage them to produce a heavy flush of mushrooms. “The spring and the fall are kind of the natural times to try to ‘push’ them” by soaking them, Rosato said, as the weather is not as hot, and therefore it’s less tricky to keep the bark evenly moist, which is essential to produce a strong flush of mushrooms and ensure the longevity of the log.
“It’s tricky. … You’re mostly going to fail unless you’re really attentive,” Rosato admitted. But he points to high prices of gourmet mushrooms like shiitake, and the superiority of homegrown mushrooms as reasons why he continues. Plus, he said, “I think it’s a magical protein source.”