How To Grow Edible Mushrooms Without a Kit

Five Functions of Fungi

Edibles. Mushrooms are packed with nutrition. They’re rich in protein, minerals, ergosterols (precursors to vitamin D), B vitamins, fiber and complex carbohydrates.

Be aware that a few species are lethally toxic, and no mushroom should be eaten unless you are absolutely certain of its identity and safety. This caution applies as much to cultivated as it does to wild species. Shiitake (Lentinula edodes) and oyster mushrooms, for example, are easy to identify when they fruit on cultivated logs. A species such as edible nameko (Pholiota nameko), however, is a close enough look-alike to the deadly galerina (Galerina autumnalis) to require as careful identification on inoculated logs as it does if gathered in the wild.

Medicinals. Fungi can act as potent synthesizers of enzymes, as enzyme inhibitors, and as natural antibiotics used in digesting food sources and defending against challengers. The pharmaceutical industry is working with many of these compounds for treatment of a number of diseases, as well as for preventing cancer and inhibiting tumor growth. Some species, such as reishi and turkey tail, have long histories of medicinal use, especially in Asian medical traditions. Certain mushroom teas and tinctures can be used daily as antimicrobials and immune system tonics.

Decomposers. In a world where all living things die, disposal and renewal are paramount. Bacteria leap onto easily broken down organic materials such as dead annual plants and manures, using them as food energy. The bacteria pass some energy on to other players in the soil food web, and eventually help convert organic “wastes” to soil humus. We see this process in a compost heap. Most decomposers, however, are stymied by the extremely strong chemical bonds that make up cellulose and lignin in dense, high-carbon tissues such as leaves, bark and wood. Far too often, we send such materials off to choke our landfills instead of recycling them right on the homestead. Enter the saprophytic fungi — the preeminent decomposers — who specialize in harvesting food energy by breaking down tough materials to their component nutrients, adding to soil humus. You can use fungi as helpful allies to build soil fertility.

Bioremediators. Sadly, many landscapes are polluted by the castoffs of industrial production. Many species of fungi can cleanse sites of heavy metal contamination, spilled oil and other toxic wastes. Here’s one application that might be of interest to homesteaders: Burlap bags filled with wood chips can be inoculated with appropriate fungal species and laid like sandbags across pollutant pathways, such as a runoff area from a livestock operation. The runoff, heavy with nutrients from manure and urine that act like toxins in natural water systems, is blocked by the “bunker spawn” levee, which absorbs it. The fungi feed on the nutrients, cleansing the flow and protecting the quality of downslope streams.

Psychoactives. Mushrooms with psychoactive properties could offer solutions in psychotherapy and the treatment of addiction. While scientific research along these lines has been severely restricted in the past because the possession of psychoactive mushrooms is illegal, federal regulators recently began allowing controlled experiments with some species in medical research.

Growing Mushrooms

Starting With Spawn. Though wild fungi survive threats due to their sheer number (billions of spores per mushroom), cultivating them requires near-sterile conditions in a “clean room” protected from bacterial and fungal contaminants. After fungi mycelium has its defenses robustly in place, it can be grown as starter “spawn” in sawdust, wood chips, wooden dowels, cardboard, and even burlap sacking and natural fiber rope.

Most homesteaders choose to leave the “heavy lifting” of starting sterile cultures and spawn to specialists able to create the right environment, but it is possible to transplant the mycelium of identified wild species into compatible substrates on the homestead. For approaches to starting fungi using natural, homegrown methods, see Paul Stamets’ book Mycelium Running: How Mushrooms Can Help Save the World.

Adding Spawn to Logs. The natural “menu” of various species will determine to a large extent which “substrate” you use to grow them — that is, which organic materials you inoculate with spawn to grow mushrooms while speeding decomposition of the materials to soil. Many species are “wood lovers,” a prime example being shiitake, one of the easiest mushrooms to grow. Because shiitake colonize recently dead trees rather than those already decomposing on the forest floor, you can cut shiitake nursery logs from living trees — preferably young, healthy trees that need to be thinned anyway. Most hardwoods make excellent substrates for growing shiitake (oaks are generally considered best).

It’s best to cut logs in the dormant period (after leaves have fallen or new growth has stopped, usually during winter). Tight bark helps protect the growing mycelium, whereas if you use a log cut after sap has begun moving in the cambium layer, the bark may slough off, leaving the mycelium exposed. In about mid-March, I drill numerous holes in the logs and “plug” the holes with purchased spawn — either sawdust or wooden dowels in which shiitake mycelium is actively growing. I then daub the plugged holes with melted wax to seal the spawn and prevent it from drying out and dying. I rack the prepared logs out of contact with the ground to prevent potential contamination.

The “spawn run,” or incubation period, can take a year, meaning harvest begins the following spring. In the driest part of summer, I soak the logs with a sprinkler about as often as I need to water the garden. After the incubation period, “fruit” logs by soaking them in a tub, imitating a prolonged period of rain, which in the wild triggers mushroom (spore) production. Soak time depends on the condition of the logs and how dry the weather has been, ranging from overnight up to a couple of days.

Tiny mushroom buttons start forming a couple of days after the soak, usually at the inoculation sites. From that point the mushrooms grow with amazing rapidity. Ideal time to harvest is just after the “veil” covering the gills has pulled away from the stem, but while the cap’s edges are still “incurled” instead of flattened out. After fruiting, a shiitake log needs about six weeks of recovery while the fungus stores energy and prepares for another round of fruiting. For a steady supply of mushrooms, I divide my total number of logs by six and fruit one batch per week. When managed as described here, shiitake logs will typically produce harvests for three to four years.

I’ve grown shiitake for many years, and now I’m experimenting with other species spawned onto logs, including oyster mushrooms, reishi, turkey tail, maitake and lion’s mane. These logs don’t need to be racked like shiitake logs, but can be laid right on the ground, half-buried horizontally, or buried vertically one-third their length in the soil, totem-style.

Adding Spawn to Other Substrates. Saprophytic fungi consume a wide variety of fibrous and woody materials, from undigested plant residue in manure to wood chips to shrub and tree prunings. You can choose from many species, spawning to the type of organic debris you want to assist in its return to earth.

One easy-to-grow saprophytic mushroom is Stropharia rugosoannulata, or wine cap stropharia. I cultivated a patch of stropharia as a partner to my asparagus. The rapid breakdown of the straw mulches by the fungus nourishes the asparagus, which aids the fungus in turn by keeping it cooler and more humid in the dense shade of the fronds. Along an interior edge of my asparagus beds, I scraped away the mulch and covered the soil with a layer of clean, perforated, soaked cardboard. I then interspersed layers of fresh wood chips and a gallon of stropharia spawn, topping off the inoculated bed with another layer of soaked cardboard. Finally, I covered the inoculation site with straw and gave it a final soaking. Soon, folding back the cardboard top revealed vigorous growth of stringy mycelium throughout the chips.

The Wild Enters the Garden

If you maintain mulches or pathways of wood chips or other organic residues, as in a forest garden (see Plant an Edible Forest Garden), a host of mushroom species will emerge in them. Even unidentified “little brown mushrooms” do the important work of building fertile soil, but some, such as blewitt or wine cap stropharia, can be harvested for the table — a case of reaping where you didn’t sow! As always, consult a field guide to ensure proper identification.

Fungi Fundamentals and Spawn Sources

Books. One of the most trusted sources of information for understanding fungi and working with cultivated species is Paul Stamets of Washington state, who has written many books, including The Mushroom Cultivator and Growing Gourmet and Medicinal Mushrooms. If you’re going to buy only one book for perspective on working with fungi on the homestead, it should be Paul’s latest, Mycelium Running: How Mushrooms Can Help Save the World. For help with shiitake cultivation (one of the easiest species to grow), see Growing Shiitake Mushrooms in a Continental Climate by Joe Kozak and Mary Ellen Krawczyk and Shiitake Growers Handbook by Paul Przybylowicz and John Donoghue. For help with identification, check out North American Mushrooms: A Field Guide to Edible and Inedible Fungi by Dr. Orson K. Miller Jr. and Hope H. Miller.

Organizations. Joining a local mycological society to learn from enthusiasts with more experience can be helpful. In my area, the Mycological Association of Washington, D.C., is a magnificent gathering of “mycophiles.” It’s an affiliate of the North American Mycological Association, which lists more affiliated clubs on its website.

Spawn Sources. A growing number of businesses sell started spawn you can use to cultivate a wide variety of species. In addition to his books, Paul Stamets sells spawn, accessories and supplies. Field and Forest of Wisconsin offers spawn, workshops, books and cultivation tools. Mushroom People offers spawn for half a dozen edible and medicinal species, plus aids for growers who want to step up to working with sterile cultures. Gourmet Mushrooms offers indoor and outdoor growing kits, spawn and books. The Morel Mushroom Hunting Club provides lots of fun products to get you started in your mushroom eating and growing adventures.

Find a Mentor. Try to find a local expert who can get you started and give you tips. I was lucky to meet Mark Jones — I think of him as “Virginia’s Paul Stamets” — who has been a tremendous source of information, inspiration and started spawn. He offers spawn, workshops and mushroom cultivation kits through Sharondale Farm. You may get strains better adapted to your climate and conditions if you find a local source.

Originally published as “All About Mushrooms” in the August/September 2010 issue of MOTHER EARTH NEWS.