Mushrooms aren’t plants and have to ‘eat’
You may have heard the expression “You are what you eat.” Some claim that certain fishes taste so good because of their diet. Here in Florida, there is a very popular fish called “Sheepshead” that eats only mollusks and shellfish, such as oysters, barnacles and shrimp. While I consider this species as OK to eat, it is not nearly as tasty to me as some omnivorous-eating critters such as grouper. Grouper will eat anything that swims in front of them, and they still are very tasty!
Most people think of mushrooms as some sort of autotrophic plant, but they are not plants at all and they too, must “eat” something to survive. The following information comes from my friend Paul Hetzler. Mushrooms such as inky cap, oyster and shiitake have a voracious appetite for wood, a substance that very few organisms eat because it is so hard to digest. Humans can derive some nourishment from certain kinds of bark, but gnawing on a two by four will not cut it for us.
Wood is made primarily of cellulose, along with varying amounts of lignin. This latter compound is to cellulose what steel reinforcing rod is to concrete. There is far less of it, but it imparts a great deal of strength and resilience. Even professional woodeating bacteria in the gut of a termite cannot digest lignin. Only certain fungi have that superpower.
There are three basic groups of wood-decaying fungi: soft-rot, brown-rot and white-rot. In scientific terms, these coteries are not closely related, even though they have the same last name.
Soft-rot fungi are very common, causing gardenvariety decay in wooden tomato stakes and fence posts. Brown rot is lesscommon. At some time or other, you’ve probably seen its handiwork. This fungus results in a blocky pattern, turning wood into miniature, spongy brown bricks. While brown rot needs moisture to do its dirty work, it is sometimes called dry rot because it readily dries out and is often seen in that condition. Both soft-rot and brownrot fungi consume only cellulose, eating around lignin like a child who avoids the Lima beans lurking among the tasty food on their plate.
White-rot fungi, on the other hand, belong to the clean-plate club, digesting every component of wood. This category of fungi can cause serious decay in hardwood trees, although a few species attack conifers. Foresters hate it, but foodies love it. It is the group that gives us Armillaria mellea, a virulent and devastating pathogen that produces tasty honey mushrooms.
Shiitake and oyster mushrooms are white-rot fungi, although they are saprophytes, akin to scavengers, like turkey vultures, not predator-like pathogens. So we don’t have to feel guilty about eating them. Regionally, shiitake farming has, um, mushroomed over the past decade. It is a source of supplemental income for farmers and a source of fun and good food for anyone who wants to try it.
Shiitake prefer oak, beech, maple and ironwood, more or less in that order. To cultivate shiitake, bolts (logs) made of one of these hardwoods are needed. Bolts are typically about 4 feet long and range from three to eight inches in diameter. Such logs will bear mushrooms for roughly one year per diameter inch. A series of holes are drilled in the logs, and these are filled with mushroom “seeds” called spawn.
As of September 2015, New York state has recognized “actively managed log-grown woodland mushrooms” as a proper — and significant — farm crop. This allows farmers to designate land they use for growing mushrooms as agricultural, making them eligible for tax breaks.
Cornell University has been quite proactive in promoting mushroom farming as a source of income for rural residents. In a three-year study that wrapped up in 2012, Cornell and its research partner institutions determined that farmers could turn a profit in just 2 years. They found that a 500-log shiitake farm could potentially earn $9,000 per year.
Steve Gabriel, Cornell’s mushroom-farming expert, points out that raising log-grown mushrooms is sustainable and environmentally friendly, in addition to being a viable income source. You can find a great deal more information on the website that Steve administers: www.cornellmushrooms.org.
On Saturday, April 28, I will be teaching a mushroom growing workshop at the Agroforestry resource center in Acra, Greene County, from 10 a.m. to 12:30 p.m. Participants will not only learn several techniques on how to grow shiitake as well as other tasty species, but will also get to actually inoculate (plant) a bolt and take it home. For registration information, call (518) 622-9820.
Bob Beyfuss lives and gardens in Schoharie County. Send him an e-mail to rlb14@cornell.edu.