Mushroom growing techniques have been developed to a high degree of technical efficiency. Proven methods exist for growing many kinds of edible or medicinal species. Mushroom growing kits can be purchased ready to be set up in an appropriate environment to produce mushrooms. Commercial quantities of mushrooms are grown using large scale production methods.

Mushroom Spawn Production

Before mushrooms of any kind can be grown, a quantity of starting material called “spawn” must be produced. Spawn is a mass of the white fuzzy mycelium of a fungus grown in a form suitable for inoculating a large quantity of substrate on which the mushrooms will be produced.

Grain spawn is prepared by inoculating sterilized rye grain in jars, with a pure mushroom culture. The mycelium grows throughout the grain and the spawn is expanded to any desired quantity by using the colonized grain to inoculate still other jars of grain. This type of spawn is convenient for starting mushrooms that grow on compost.

Dowel spawn is produced by inoculating bags of sterilized wooden dowels. When fully colonized, the dowels are driven into holes drilled in logs, or the dowels can be added to bags of wood chips or sawdust. Dowel spawn is used to culture wood-inhabiting species.

Growing Mushrooms in Compost

The classic commercial button mushroom (Agaricus bisporus) and the larger portabello (which is the same species allowed to get well past the button stage) is grown in tremendous quantities on mushroom farms around the world. Since the natural habitat of its wild predecessors was in pastures, this species is grown on a substrate of horse manure compost. Other species grown on compost include Coprinus comatus (shaggy mane) and Lepista nuda (blewit).

A number of variations on preparing mushroom compost exist, but two basic formulas are (1) horse manure, cotton seed hulls and gypsum, and (2) chicken manure, wheat straw and gypsum. The compost is inoculated with spawn and the spawn is allowed to completely colonize the substrate. Production of mushrooms is initiated after a peat-based casing layer is spread on top of the colonized compost.

Growing Mushrooms on Logs

Reishi mushrooms (Ganoderma lucidum), shiitakes (Lentinula edodes), hen of the woods (Grifola frondosa), lion’s mane (Hericium eriniceus), and oyster mushrooms (Pleurotus spp.) are all wood-decomposing fungi suitable for log cultivation.

Most species prefer hardwoods such as oak, maple, elm, cottonwood and alder, although a few species do well on conifer wood. The logs are best cut just before winter when their sap content is highest. Logs should be allowed to age for a month or two, but should be used before they dry out. Any size of log should work, but if the logs are big and heavy they take longer to colonize and are difficult to transport and handle. A length of about a meter and a diameter of 10-30 cm is good.

Dowel spawn is driven into holes drilled into the logs. The holes are sealed with wax to keep the inoculum from drying out before the fungus can become established in the wood. Under the best of circumstances, the logs will not be ready to produce mushrooms for six months, with a year or more being more typical. When the logs begin to show mycelia on their cut ends, they are close to being ready for fruiting.

Fruiting is initiated by soaking the logs in cold water for twenty-four hours followed by further incubation in high humidity with fresh air. Logs can produce flushes of mushrooms periodically for several years.

Growing Mushrooms in Sawdust and Wood Chips

Mushroom species that do well in logs can also be grown in bag culture using the same kinds of woods. Dowel inoculum, liquid spawn, or grain spawn is added to bags of sawdust and/or wood chips and thoroughly shaken. After two or three weeks, once the mycelia have grown throughout the wood, the bags are shaken again and incubated an additional couple of weeks until the substrate is fully colonized.

Then the bags are usually slit open and soaked in cold water for a day and incubated in high humidity with fresh air exchanges. Mushrooms are produced in as little as five weeks with this method and two or three flushes, with rest periods in between, can be achieved before the nutrients are used up in the wood.

Many mushroom growing kits come with a substrate of sawdust and/or wood chips. These kits are easy to set up since they come ready to produce mushrooms in a relatively short time once the correct conditions are established.

Other methods of mushroom growing exist for research or laboratory purposes, but the methods outlined above are the ones usually used by both commercial and hobby mushroom growers.

References

Stamets, Paul, and Chilton, J. S., 1983, The Mushroom Cultivator, Agarikon Press, Olympia, WA

Stamets, Paul, 1993, Growing Gourmet and Medicinal Mushrooms, Ten Speed Press, Olympia, WA

Note: This article was originally published at Suite101.com.

Perhaps the latest monograph on protein-protein interactions in the genus Schizophyllum is not high on your reading list. Not only that, but if someone gives you one more “giant color treasury of mushrooms” you are going to throw away your coffee table! There are some readable, informative, and yes — even entertaining — books from the world of mycology that might be just what you need. Here are three that any fan of the fungi will appreciate.

The Fungus Fighters

The Fungus Fighters, by Richard S. Baldwin, chronicles the work of Elizabeth Hazen and Rachel Brown, who together are credited with the discovery of the first safe and effective antifungal drug — nystatin. Fungal infections are relatively rare and you may not give them much thought (after all, athlete’s foot is not the most serious of afflictions).

However, when a serious deep fungal infection strikes, it can be lethal. Fungi are eukaryotic, as are humans, so it is difficult to find drugs to attack them that won’t also attack the patient’s cells at the same time. If you like science and a bit of a mystery, you’ll enjoy reading about the dedication and hard work of these two researchers, who made an important contribution during a time when women researchers were still seldom found in the laboratory.

Mushrooms, Molds, and Miracles

Dubbed “A fascinating journey into the strange realm of the fungi — man’s greatest friends and deadliest foes,” Mushrooms, Molds, and Miracles, by Lucy Kavaler, takes the reader on a wide-ranging journey through mycological history. Well researched, and with a little something about everything fungal, Kavaler touches on brewing and bread making, toxic and edible mushrooms, the discovery of penicillin, the great potato famine, fungal biotechnology, and even extraterrestrial life.

It’s a bit dated (1965), but outside of the biotechnology parts, it does an excellent job of describing the great help, as well as the great destruction, rendered by the fungal kingdom.

Trees and Toadstools

Rodale Press published a wonderful book in 1947 called Trees and Toadstools, by M. C. Rayner. It doesn’t seem like something Rodale would touch these days, but we can be glad they did back then. The original edition was published in England in 1945.

In a concise and highly readable 85 pages, Dr. Rayner introduces the world of woodland fungi and more specifically the fungi that inhabit the roots of nearly every tree you see. Without these “fungus roots” (mycorrhizae) most trees would be in a bad way. It is long out of print, but this gem can occasionally be found in used bookstores.

References

Mushrooms, Molds, and Miracles, Lucy Kavaler, John Day Company, NY, 1965

The Fungus Fighters, Richard S. Baldwin, Cornell University Press, Ithaca, NY, 1981

Trees and Toadstools, M. C. Raynor, Rodale Press, Emmaus, PA, 1947

Note: This article first appeared at Suite101.com.

The story follows a husband and wife who earn a meager living by hunting wild mushrooms. During the warm months, Lucien and Regina gather a diverse bounty of edible fungi from area woodlands and then go door-to-door selling them to upscale restaurants. When winter comes, and mushrooms go into dormancy, the couple must find temporary work as kitchen laborers to make ends meet. They constantly struggle to get by, dependent on variables of rainfall and temperature–living without the protection of any safety net.

Jason grew up foraging with his family on the West Coast—Oregon and Northern California. Mushrooming is something he’s passionate about. And, because it really hasn’t been shown before in a fiction film, Cortland decided to make foraging the central action of his latest project.

How to Fund a Mushroom Foraging Film

The producers drummed up some initial funding for the project on Kickstarter, and that helped them finish the initial production phase last Fall.  Now, to put on the final touches, the film is up for a final round of funding on United States Artists. I asked Jason how they got their funding, and why they decided to go with United States Artists.

“We decided to work with United States Artists (USA) this time for a few reasons. First, because USA is a non-profit organization, all donations to our film are tax deductible. That’s something we wanted to offer our donors. Second, because USA is somewhat selective about who they accept, the association helps raise the pedigree of the project to some degree. That can help attract other grants and festival invitations. Third, and most important, because we’re former recipients of grants from the Texas Filmmakers Production Fund, we qualified for a matching grant from The Austin Film Fund. For the first $3000 we raise, donors effectively double their donations. It’s a sweet deal and we’re very appreciative of the support.”

People can donate to the cause at the film’s USA web page.

“United States Artists accepts artists who have previously won a grant, residency, or fellowship—so the lineup is somewhat curated based on having an established track record in an artistic discipline,” Jason continues. “That’s the main qualifier—once they vet you, it’s very easy to get a project up and running. They even offer an online training session and one-to-one support to help artists learn about developing their fundraising strategies for both their immediate needs and their long-term career. So it’s a pretty cool organization.”

The film has been selected for  the  “Gotham in Progress” European film market in November, in Poland. Jason and Julia will both be going to Poland. They will spend a week or so meeting European sales agents and distributors who might be interested in the film.

Now, Forager is almost done—but not quite. According to Jason, there is still some work to do.

“We’re at the “fine cut” stage—which means that we’re still making small adjustments to scenes, but the overall structure is in place. We’ll lock picture in the next few weeks, and then all the technical finishing work begins to prepare the film for distribution—adding an original score that Chris Brokaw is composing, editing and mixing sound,  color correcting all the footage, and creating an HD master.  So, creatively, we’re very close to being finished—but we have a couple months of technical work left to do to make sure the film looks and sounds right when it’s projected for an audience. This is, of course, a very precise and costly part of the filmmaking process.”

When Julia and Jason moved to New York to start developing the project, he joined the New York Mycological Society (NYMS) to learn about the regional species of edible mushrooms. “The core members of the NYMS really took me into their inner-fold and I soon was drawn into the deeper study of mycology,” he explains. “Learning about taxonomy, using keys, microscopy, taking workshops and attending large forays to learn from mycologists like Tom Volk, Tim Baroni, Kathie Hodge, and Rod Tulloss; that experience didn’t just change the script, it’s really permanently changed what I think about and do with my free time. I’m a mushroom geek for life.”

According to Jason, “It’s a unique and beautiful world that was begging for a proper cinematic exploration.”

Check out the trailer for Now, Forager:

More on Now, Forager

Keep an eye on the Now, Forager Blog.

There Will Be Mushrooms: New Film Explores the Emotional Hazards of Foraging

Interview with Jason Cortlund at Mushroom Palace

Figure 1. Location of Black Forest Regional Park (A)

I don’t get out on many mushroom hunts these days, but with the record one-day rainfall of last week, I figured that over the weekend it would be as good a time as any to get out. So, on Sunday, September 18 we took a short trip over to Black Forest County park in El Paso County just to the northeast of Colorado Springs.

It was a nice day and, although the ground had started to dry up already, it was still moist under the duff. The park is characterized by sandy soil and a mixture of tall pine trees and clumps of scrub oak (see Figure 1 for map location).

Figure 2. A small late summer collection of Colorado mushrooms

I thought we would come up with a lot more, but we did manage to bring home six collections. After spreading them out on a table and setting some up for spore prints, I tried my best to identify what I could (Figure 2).

One needed no research and was obviously what is known as the lobster mushroom, which is of course actually some (usually difficult to identify exactly Russula or Lactarius) mushroom species covered with a reddish-orange parasitic fungus called Hypomyces lactifluorum . Supposedly edible, but no thanks.

Spore prints were not very successful. Apparently the mushrooms were a little dry, but one did drop an ample amount of pinkish brown spores. Using Arora’s Mushrooms Demystified, it keyed out fairly reliably to Pleurotus cervinus, although the cap was a little paler than what is seen in most photographs . I really should join the local mycological society so I can get more familiar with the local species.

Figure 3. Lobster mushrooms

Lacking spore prints, compounded by my general lack of knowledge about Colorado fungi, I was unable to make much headway on the others, although the clustering species with decurrent gills could possibly be Hygrophoropsis aurantiaca (but I wouldn’t bank on it). They were a nice yellow
color with inrolled cap margins and a slightly brownish center region on the cap,  growing in attractive clumps (Figure 4).

I dampened some of the caps from specimens that I had not obtained spores from in the hope that they would rejuvinate and perhaps yield something. I’ll check  again in a day to see if anything shows up. Without spores, there isn’t much chance of getting a good ID. I am sure someone who is more familiar with the local mycoflora could probably recognize them though.

I was pretty good at identifying Texas mushrooms, but I am admittedly out of practice. I need to work on my Colorado mycology chops!

Figure 4. Cluster of mushrooms with decurrent gills

Figure 1. A Vertical Farm Concept (iied.org/flickr.com)

I recently read The Vertical Farm, Feeding the world in the 21st Century, by Dickson Despommier (2010, Thomas Dunne Books, St. Martin’s Press, New York, NY) and I also got a chance to chat with him on the phone to get some information for an article I wrote for a magazine. Dr. Despommier is a microbiologist and a driving force behind the vertical farming (VF) movement. Vertical farms are urban structures designed for food production. I highly recommend the book to get the full scoop or you can also learn more at The Vertical Farm website. Figure 1 is probably enough to give you some idea of what one might look like. Things are just getting started in the VF world right now but several projects are under way around the globe.

However, I got to thinking, how could mushroom growing fit into the VF scheme of things? The carbon dioxide/oxygen linkage between plants and fungi seems like it is ready-made to play a role in any vertical farm intent on maximizing efficiency. There could be some favorable humidity conditions available in a VF building using hydroponics that could be taken advantage of as well. I visualize something like this:

• Mushroom spawn can be produced in a controlled environment within the VF building.
• The CO₂ laden air from the spawn room can be slowly vented into the plant growing areas to enhance photosynthesis.
• If Agaricus is the species in cultivation, it could be grown in the inner parts of the structure since there would be no need for light.
• Light-requiring species could be grown in bags and moved about on rolling carts into areas of light when it was time to induce fruiting.
• When it was time to induce a flush of mushrooms the more oxygen rich moist air from the plant environment could be circulated into the grow room, or as mentioned, the spawn bags could be moved into or near to the plant section.
• Mycelium is already being used for CO2 supplementation by some growers (see Figure 2).

Figure 2. Exhale Bag for Carbon Dioxide Production (Philip McIntosh)

These ideas are very general I realize, but they do layout a framework to be pursued. After I had thought about this, I ran across a brief notice during my article research about a VF project in Manchester UK that plans to include mushroom growing. Details on that project are sketchy so I am not sure to what extend the mushroom growing will be integrated into the overall design.

I figured others have probably though of this idea too, so a quick web search reveals a couple of things, but they are mostly conceptual and no one to my knowledge is actually putting any sizable mycocultural modules into a VF operation at this time.

One interesting concept is SPORE v2 described at ARKFAB (Figure 3). It is a design for a specialized growing facility but I think it is a stretch to call it a vertical mushroom farm. It’s more of a really cool design for a regular mushroom farm and it’s not very vertical. Since it is designed to be a stand alone unit, it is not really along the lines of how I envision mushroom farming being integrated in to a VF structure. But, could the SPORE v2 be installed somewhere within a larger VF building? It sure looks like it could. Tragically, the founder of ARKFAB recently died in a motorcycle accident and email messages are bouncing, so for now I can get no further information on SPORE v2.

Figure 3. The ARKFAB SPORE v2 design (ARKFAB)

It looks like Plant Chicago has the right idea. Plant Chicago is a nonprofit dedicated to promoting sustainable food production, entrepreneurship, and building reuse through education, research and development. According to the diagram (Figure 4) they appear to be putting some thought in to exactly how mushroom farming would fit into an overall plan to include hydroponics as well as aquaponics. It’s a work in-progress, and according to Melanie Hoekstra, Operations Manager at The Plant, the substrate has been inoculated but no mushrooms have appeared yet..

There are plenty of references to growing mushrooms “vertically” in bags, or stacked vertically on shelves, or vertically on a wall, etc. But, there seems to be very little information about anyone who is really putting serious thought and effort into true vertical mushroom farming with the same scope and breadth of vision as Dr. Despommier lays out in his book. So, the question remains—who will build the first truly integrated mushroom growing operation in a vertical farm?

Figure 4. Plant Chicago Design Includes a Mushroom Facility (Plant Chicago)