mushroom cultivation

Here are a few suggestions on cultivation, which might be useful to folks interested in growing their own mushrooms.

Like other sorts of gardening, this can be a really easy and/or inexpensive effort – if you buy a pre-inoculated log kit or if you inoculate mushrooms in a ground bed. On the other hand you can put more work and/or money into it by inoculating logs yourself and maintaining more logs or beds. If you end up too busy this season to do anything else, you can always buy from local mushroom growers and foragers. I have put together some information here about in-ground mushroom cultivation, log cultivation, and general information about workshops, log kits, legal issues, my Facebook page, and cultivation resources. This is not meant to be a guide to mushroom cultivation, but an introduction – so that you have an idea what you are getting into.

My bias is for growing shiitake and oyster mushrooms on logs outdoors, since I believe the quality of log-grown mushrooms is unparalleled. But you can also grow mushrooms on soil, straw, wood chips, sawdust, coffee grounds and agricultural waste products. These can be contained in plastic bags, bins, bottles or in ground beds. I have a bit of experience with growing mushrooms on or in the ground, but you should talk with someone else if you are interested in these other methods. Ron Spinoza of the Minnesota Mycological Society is a good resource, as is Fred Finch of Back Forty Farm– a local farmer that grows mushrooms on straw and manure. You can contact him at fred.finch@gmail.com.

In-ground mushrooms

If you are interested in a really easy project, I would try growing mushrooms in an outdoor mushroom bed on or in the ground. Here is some info about where to start:

mushroom varieties: There are a number of varieties to choose from, including Wine Caps, Almond Agaricus and bluets. I tried the wine caps last year, and I found them only passable in taste, while some people really enjoyed them. I plan to try others next year. You can purchase spawn from suppliers like Field and Forest Products

light: these varieties need light to grow, while others can’t tolerate light. Ask your spawn supplier which will work outside. I would recommend starting a mushroom bed in a fairly shady area.

substrate: To get them started you mix the spawn with soil, wood chips or whatever is required for the mushroom variety, then spread on the ground. Mulch with straw to keep in moisture and keep out direct sun.

watering: I would water a couple of times after you inoculate or during drought, but generally you need not water at all.

cost and yields: A five and a half pound bag of sawdust spawn will cost you $25 to $30 and can cover as many as fifty square feet. I have gotten ten pounds of wine caps per bag in a season. Most other varieties are more fickle and less productive, but arguably tastier.

when to inoculate: in the early spring when temperatures are generally above freezing at night. Others such as bluets can be started in the fall, since they take more than a season to get started anyway.

harvest time: spring or late summer and autumn, depending on the mushroom variety.

Large log cultivation

A great way to start log cultivation is with the totem method on large logs. This is a good way to grow oyster, lion’s mane, or other mushroom species, but oyster is the most forgiving and prolific.  In short, spread sawdust spawn between sections of large-diameter logs, and then cover with a plastic bag for a few months, or until a white film (the mycelium) forms on much of the log surface.  Then pull the bag off.  Field and Forest Products has complete instructions on how to do this in their catalogue, or view my 2012 blog post on large diameter log inoculations for more details.

laying area: The log should be kept in a shady location – at least 80% – and you won’t want to move it once it is set up, since these can be quite heavy! You can also shade the log with a 80% shade cloth tarp, which I will be offering at the farmers market this year.  Your mushroom log will also benefit by some protection from the wind with a vegetative or solid barrier, but you also should allow some air movement around the log.  Even in a shady spot, you will need to protect your logs from frost in the winter, which you can do with burlap or a combination of burlap and plastic, though shade cloth works well if you are already using that.  Alternately, you can place your log a garage or shed during the winter.

watering: Your log may need watering every week or two during the growing season of the mushroom, since they won’t fruit without water.   For oysters, this is typically during the late summer and fall, so I would plan on watering during that time, especially since we often have drought during that time in the upper midwest.  A garden hose and sprinkler may also be necessary to water the logs as needed.

When to inoculate: late winter or early spring, no later than May if you can manage it.

What you need: You will need a large diameter log – 6” to 12” in diameter cut into 8”-16” long sections. The species of wood you use should be paired to the species of mushroom you want to grow (see “Pairing mushroom and log species” below).  You will also need to be careful about when the log is cut, the shape it’s in, and how it is kept before inoculation.  I usually cut a 2” or 3” cap to put on the top end and perhaps the bottom too, though you can alternately cover with newspaper or paper bag attached to the top. You also need some sawdust spawn from a mushroom supply company like Field and Forest Products and a plastic bag (or two) large enough to loosely enclose your log.

Logs: For mushroom mycelium to thrive on a log, the wood needs to be strong live wood, and may need to be freshly cut in a dormant state (generally before the tree leafs out or the sap begins to run).  Aspen, which is a good wood for oyster mushrooms, can be harvested any time of the year for cultivation except for the month just as the trees are leafing out.  This eliminates most windfalls, and all logs that have been sitting in your yard since last summer. Those old logs already have other fungi growing in them, even if they aren’t visible. I generally use logs between three and eight inches in diameter. Any smaller and they will too easily dry out. Any bigger and they will be less productive, and heavy to boot!

If you aren’t sure which logs are mushroom safe, or if you don’t have access to fresh logs, you can purchase them from me at the farmers market, and they should be available at the Egg|Plant Farm Supply in St. Paul in the late winter and spring.   I should have red oak, bur oak, and aspen (also known as “pople”) logs up to three or four foot in length.

Harvest time: If you inoculate an oyster log in the spring you should get fruitings by the fall, while you’ll have to wait longer for Lion’s Mane or other species. Your totem logs should keep producing for several years, though they will produce less after the first couple of years.

Identifying your harvest: Make sure you are familiar with the mushroom you growing before you harvest one off your log, since mushroom poisoning is serious. If you have any questions about a mushroom, get the help of an expert to identify it for you. The Minnesota Mycological Society is a good resource for mushroom identification.

Harvest yields: I have heard that yields can be as high as a pound per foot of mushroom log, but I haven’t had enough experience to back that up. Try it and see for yourself!

Small log cultivation

In small log cultivation, you start by inoculating the logs: drill holes in logs, place spawn (mycelium “seeds”) into the holes, and cover the holes with wax. The logs need to sit for several months at least before they are ready to fruit, which gives the mycelium a chance to colonize the log.

When to inoculate: late winter or early spring, no later than May if you can manage it, but I always end up inoculating into May or June.

What you need:
to inoculate just a few logs
You will need a log, plug mushroom spawn, a drill and 5/16″ or 8.5 mm drill bit (ideally with stop collar), a rubber mallet, a tub of plug wax (no heating required). You will also need a shady spot or 80% shade cloth (I will be offering this at the farmer’s market this year) and you may need a garden hose and sprinkler to water the logs as needed. If you want to concentrate fruitings, you will need a large tub to soak your logs in. Even in a shady spot, you will need to protect your logs from frost in the winter, which you can do with burlap or a combination of burlap and plastic. A wicker basket may also work.

for more than a few logs
You will need a log, sawdust mushroom spawn, a drill and 7/16” or 12 mm drill bit (ideally with stop collar), an inoculator tool, cheese wax, a pot or large tin can with lid, a hotpot or camp stove, and wax daubers. I would add that a high speed drill or adapted angle grinder – at least 5,000 rpm – may be worth the expense if you plan to process more than a few dozen logs. You must use a 12 mm bit when using a high speed drill.

laying area: The log should be kept in a shady location – at least 80% – and you won’t want to move it once it is set up, since these can be quite heavy!  You can also shade the log with a 80% shade cloth tarp, which I will be offering at the farmers market this year.  You will also need a framework of some sort to distance the cloth from the logs in damp conditions.  Your mushroom log will also benefit by some protection from the wind with a vegetative or solid barrier, but you also should allow some air movement around the log.  Even in a shady spot, you will need to protect your logs from frost in the winter, which you can do with burlap or a combination of burlap and plastic, though shade cloth works well if you are already using that.  Alternately, you can place your log a garage or shed during the winter.

Pairing mushroom and log species: Shiitake, Lion’s Mane, Maitake, and Reishi all grow well on hard hardwoods like oak or maple, while soft hardwoods like aspen or red (soft) maple are good for Oyster or Beech mushrooms. There is a fairly good guide to matching tree to mushroom species in the Field and Forest Products catalog. You can try unusual pairings of tree and mushroom species – say shiitake with willow- but you won’t get as many mushrooms as you would if you used a hard hardwood. More on logs below.

Mushroom species: In the next month or so you should consider what species you’d like. Oyster and shiitake are good ones to start with. Supply companies like Field and Forest Products or Fungi Perfecti have limited stock of more unusual species or strains, so sometimes you have to wait until they make up more. I’d especially recommend Field and Forest Products. They are great about answering questions and helping you to figure out what to order, though I would do some research first. Start by explaining to them what your setup is, and they will have some good suggestions. Orders can take two weeks if they have everything ready or four weeks or more if they need to make up new batches of spawn for you. The safest course would be to order spawn by February; you can ask them to ship it to you so that it will arrive at a certain time, so that it isn’t languishing in your refrigerator.

Logs: For mushroom mycelium to thrive on a log, the wood needs to be strong live wood, and freshly cut in a dormant state (generally before the tree leafs out or the sap begins to run). This eliminates most windfalls, and all logs that have been sitting in your yard since last summer. Those old logs already have other fungi growing in them, even if they aren’t visible. I generally use logs between three and eight inches in diameter. Any smaller and they will too easily dry out. Any bigger and they will be less productive, and heavy to boot!

If you aren’t sure which logs are mushroom safe, or if you don’t have access to fresh logs, you can purchase them from me at the farmers market, and they should be available at the Egg|Plant Farm Supply in St. Paul in the late winter and spring.   I should have red oak, bur oak, and aspen (also known as “pople”) logs up to three or four foot in length.

Watering: many cultivators regularly water their logs during their resting phase for optimal yields, and soak their logs for a larger period to induce concentrated fruitings.  A garden hose and sprinkler or bucket/barrel are necessary to water the logs as needed.  If you want to concentrate fruitings, you will need a tub to soak your logs in.

Harvest time: If you inoculate late this winter or early Spring, you may get harvests in the fall. There will be less of a delay if you inoculate on soft hardwoods (as with Oyster, etc.), and more of a delay (to the tune of a year or more) if you inoculate with Maitake or other slow growing species. If you treat your logs well, shiitake on oak logs will keep fruiting for up to six years.

Identifying your harvest: Make sure you are familiar with the mushroom you growing before you harvest one off your log, since mushroom poisoning is serious. If you have any questions about a mushroom, get the help of an expert to identify it for you. The Minnesota Mycological Society is a good resource for mushroom identification.

Harvest yields: I have had shiitake yields of nearly a pound per four foot log, but my average has been more like 3/4 of a pound. I have heard that one should expect 1/4 pound over the life of a log for a 30″ log. A pound will just barely fit in my open hands, and is plenty for a couple of omelets and a soup. They also dry and rehydrate beautifully.

General stuff

Workshops: I will be leading mushroom cultivation workshops throughout the season, though especially in the spring, where I will talk about mushroom reproduction and demonstrate common inoculation techniques, log stacking configurations, watering, pests, and the like. Check out the event calendar for workshop dates. Generally there is a fee for attendance that will vary depending on the venue. If you are interested in hosting a workshop for an organization, business or garden, feel free to email me with a proposal.

Mushroom Log kits: If you find the prospect of inoculating your own logs too intimidating, you can purchase a log kit. These are logs that are ready to fruit right away. There are many spawn supply companies that offer log or bag kits for many varieties of mushrooms. If you are interested in shiitake or oyster log kits, I will be offering them for sale in several venues this next season. Check out the mushroom & kit finder for log kit availability.

Legality: I’m sure Minneapolis is not the only city that has limits to the way one can store wood in one’s yard. With only a small stack of mushroom logs in your backyard you shouldn’t have any problems, but you should know that these stacks may not be compliant with the zoning code in your municipality. My advice is to keep your stacks neat or inconspicuous, and be on good terms with your immediate neighbors. In Minneapolis anyway it is very unlikely that you will have problems unless a complaint is filed with the city by a neighbor.

Cherry Tree House Mushrooms on Facebook: is another way to follow what is going on at CTHM, including posts on inoculation or cultivation progress.

Useful references: I especially recommend Growing Shiitake Mushrooms in a Continental Climate by Kozak and Krawczyk (owners of FFP) and Shiitake Growers Handbook by Przybylowicz. The authors are working on a revision, which they expect to be available this year. I would get one of these if you want to inoculate more than a few logs. Even if you don’t want to purchase a book, I would request a catalogue from a spawn supply company like Field and Forest Products or Fungi Perfecti. These companies can be a great resource for information and advice, and I generally pepper my spawn and equipment orders with questions about cultivation. Further, many university agro-forestry programs have published online guides to mushroom cultivation that I have found helpful. Cornell University is a good example. The Minnesota Mycological Society may also be a good resource. They seem to be focused more on foraging, but they do have a cultivation committee, and there are some very knowledgeable folks in the organization. The North American Mycological Association (NAMA) is another good resource. Both of these organizations have yahoo groups, and I have learned a few things from the NAMA group.

I hope this has been useful to you – at least to get started. Let me know if you have any questions, or just want to chat about what you’d like to do.

Contact Farmer Jeremy McAdams at 612-205-8599 or fill out the form below:

Cherry Tree House Mushrooms LLC, 827 15th Street, Clayton, WI, 54004

 

3 thoughts on “mushroom cultivation

  1. I planted some sawdust spores of wine caps under my fruit trees. Generally I don’t water my trees as there is enough throughout the year, except when my fruit trees are fruiting. Then I usually water them a bit every day or every other day. Will this be damaging to my mushroom spores? Do you know? Can you water them too much? I live in the south so it gets pretty hot and drys out pretty fast here.

    • I think the main danger of over-watering is that you may invite some molds to thrive in there, though wine caps can be a very robust mushroom. I’d recommend watering no more than once a week for the mushrooms, and that is probably better for your trees anyway, since the water will percolate down further if you water for many hours once a week. I hope that helps!

  2. We are a bunch of volunteers and opening a brand new scheme in our
    community. Your website provided us with useful information to work on. You have performed a formidable
    job and our whole neighborhood can be grateful to you.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s