Growing Shiitake Mushrooms

When trying to find things to grow on my small homestead farm I look to nature to see what naturally grows here in the mountains of North Carolina. I looked around and found that blueberries grow wild so I started with 125 blueberry bushes. Then I thought of apples since I see lots of wild crab apple trees. The problem with domesticated apples and other fruit is that I happen to live in an area that is considered a temperate rain forest. This means that we get about 80 inches of rain annually. That much rain makes it difficult to grow many things like fruit and berries because of diseases caused by fungi and molds. Well, I thought, if fungi like to grow here then that’s what I’ll grow. Why fight Mother Nature? After doing a little research I found that what I’d need would be oak logs, shade and water. My wooded acreage provides me with all the oak and shade I need. Several creeks and lots of rain provide the water. In my first year I inoculated twenty five logs as a test run. They produced very well so every year I add additional logs to increase production and replace depleted logs. Logs should last from three to eight years depending on the type of wood used and the size of the logs.

I started giving mushrooms to friends, using them for barter, then selling to a local restaurant. This year I will be at the local Farmer’s Market as I approach having 200 logs in production. I also eat lots of fresh mushrooms and dehydrate them for off season use. Growing mushrooms is a lot of work up front but once the logs are inoculated subsequent work in the following years is minimal. Holding a mushroom inoculation party makes the work fun and quick and everyone goes home with a log or two.

What you’ll need:
1. Oak logs about 3 to 8 inch in diameter and 30 to 42 inches long. Just remember that you’ll have to pick them up and move them around occasionally and the larger ones tend to get heavy, especially when wet. Shorter logs tend to dry out faster so size your logs according to your lifting capabilities. You can also use other types of trees like Maple, Ironwood, Sweetgum, and other hardwoods but Red Oak or White Oak is best. Shiitake means “mushroom of the oak” for a reason. The bark on Maple does not hold up as well as Oak and Maple will also not last as many seasons as Oak. There are also certain types of trees that should not be used such as any Conifer, soft hardwood, Locust, Black Walnut, Ash or Elm. If you cannot cut logs yourself you can order them from a firewood supplier. Just make sure they are fresh logs.
2. Mushroom Spawn in any of several forms. The spawn is mushroom mycelium mixed with some type of substrate. I purchase sawdust spawn which is best for preparing a lot of logs but you can also get wooden dowels that contain the mycelium which is easier for small runs. Mycelia are spores which is like the seed of the mushroom. When in contact with a suitable food (wood) and the right amount of moisture, it grows and produces fruit (mushrooms). Spawn may be stored in the refrigerator for several months. Since the supplier cannot always ship your spawn immediately, order in advance and you’ll have it when you need it.
3. Tools such as a drill and inoculating tool if using sawdust spawn or a hammer if using dowels. I use an angle grinder that has been outfitted with a special bit to drill holes of the correct diameter and depth for my inoculation tool. If only doing a few logs use the dowels, and drill holes with any drill but if doing many logs it is worth the investment to get the angle grinder and special bit. Your wrists will thank you and you will save yourself many hours of drilling.
4. Wax is used to seal the holes once the log has been inoculated. I suggest using cheese wax. I once used beeswax only to have it all melt in the summer heat and leak out. I use a dedicated $5 crock pot from Goodwill, to melt the wax and a special dauber to apply it but you can use any small paintbrush.
5. A shady cool spot to store your logs. Eighty percent dappled shade is just about right and protected from wind especially if you are in a dry area.
6. Water to soak the logs or a sprinkler system. I store my logs next to the creek and throw them in to soak them when needed, or just let the rain keep them wet. If a creek or pond is not available you can use a garden hose with a sprinkler or any tank of water such as a stock watering tank, a 55 gallon drum or old bathtub.



What to do
1. Cut logs to size. This is best done when the trees are dormant as the bark has a better chance of staying tight. Cut them in winter or early spring about a week before inoculating. Do not use tree limbs that have fallen or any tree that shows signs of decay or disease. Do not let logs sit on the ground for too long as they will pick up competing mushroom spores from other strains that will compete with or kill the Shiitake spawn.
2. Drill holes according to the type of inoculating method. Holes must be drilled to the diameter and depth as set forth by the dowel or plunger type inoculation tool. Instructions will come with whatever type inoculate you order. Do not predrill lots of holes with the idea that you’ll come back and fill them later. Only drill what you can fill and seal in a short time. Holes should be drilled in a diamond pattern. Drill a lengthwise line of holes 6 inches apart and then roll the log about two inches. Drill another set of holes 6 inches apart this time staggered with the previous line of holes, thereby creating the diamond pattern. The pattern is not critical; you just want to get the spawn spread out evenly throughout the log.
3. Insert spawn. This can be either dowels for small jobs or sawdust spawn for larger jobs. Use the special plunger tool with sawdust spawn. Make sure that the hole is neither under or overfilled. The top of the spawn should be slightly indented leaving room for the wax seal.
4. Seal holes with cheese wax. Make sure the hole is thoroughly sealed to keep the spawn from drying out and other spores from entering your logs. Be careful to not overheat cheese wax. If overheated it can ignite. A crock pot is usually safe.
5. Set completed logs in shade. I stack mine up off of the ground on other oak logs or on pallets to keep foreign spores from entering since I am located in a very wet area. Shade should be dappled with sunlight, about 80% shade. Logs must not be allowed to dry out during incubation or the mycelium will die. In dry areas keep them close to the ground.
6. As the logs incubate, the mycelium that you have injected will begin to grow and form a network of tiny “roots”. When the temperature and moisture content is right the logs will start to pin or show signs of mushrooms. The mushrooms contrary to popular belief do not pop out of the holes that you drilled but can for anywhere on the log. Fruiting usually begins in autumn if it is not too cold, other conditions are right and you have used sawdust spawn. Doweled logs will normally produce one year after inoculation. Some strains do better in warmer weather and some in cooler weather. I use a broad range strain which produces in a wider variety of conditions. When conditions are right and the logs are ready to produce you can soak the logs for about 24 hours then remove them for forced fruiting or you can just wait for a heavy rain. There are different ways to stack them but I usually stack mine log cabin style. As in my case, too much rain while mushrooms are growing can cause them to get soggy. I sometimes need to cover the logs with a tarp while they are fruiting. They are best picked while the caps are still curled under. If left on the log too long they flatten out and begin to deteriorate. Check logs frequently especially in wet weather as I have often been surprised by a huge flush of mushrooms.
7. Just as you like mushrooms so do a host of other creatures such as slugs, squirrels and other furry friends. You can set beer traps for slugs. I am trying ducks this year as I hear that ducks love slugs. The biggest danger to your logs is that they become too dry so make sure proper moisture content is maintained.



Keep in mind that like growing any crop, what you do depends on many factors such as climate, type of wood, and strain of mycelium used, some of which may be quite different from what I have described. Do a little local research to see what works best in your neck of the woods. Don’t be intimidated either. The logs will pick up mushroom mycelium with or without your help. This is nature’s way of decomposing wood fiber. All we are doing is helping the logs to grow the kind of mushroom that is good to eat. If you want to just dip your toe into the mushroom growing world and this just seems like too much of a commitment, you can also buy a small starter kit with everything you will need for about five logs. You can even get a table top farm to stick in your kitchen garden that is guaranteed to produce mushrooms. While there are many suppliers of tools and spawn to produce mushroom logs, I can recommend the following two from personal experience. Both of these companies can also supply you with books and free information to help your inoculation go smoothly. Field and Forest Products 1-800-792-6220 www.fieldforest.net Fungi Perfecti 1-360-426-9292 www.fungi.com