Shiitake mushrooms are supposed to be one of the easiest mushrooms to cultivate. Partly because you don't have to deal with soils and substrates and partly because inoculating logs with just one type allows you to better recognize and identify the shiitakes.
Making your own mushroom logs is credibly easy. But with that said, if you plan to do more than 100 plugs or if you plan do start new logs every year, it will really pay off to purchase a special bit for an angle grinder. When I ordered 100 shiitake plugs, it took me the better half of two days to get them all done! Phew! No one told me that drilling one hundred holes into oak logs was going to be hard using just a home-use power drill. Well, maybe someone did, but I wasn’t listening.
Let's get started!
Firstly, you need 4-6″ diameter hardwood logs with the bark intact. Preferred woods include, but are not limited to: white oak, red oak, poplar, maple, alder, etc. Avoid evergreen hardwoods (live oak) and evergreen conifers (fir, cedar, pine, etc.). How many logs you need will depend on how many mushroom plugs you order. I put about 10-12 plugs in each of my 2-3' foot long logs. Try your best to find logs with a maximum length of four feet so that it is easier to handle them and also to soak your logs later if need be.
You will also need some sort of power/electric drill with a 5/16″ drill bit. The size of the drill bit needed will also depend on the size of inoculated dowels you order, but 5/16" is a typical size. There are several companies online that you can order mushroom plugs from and a simple Google search will help you find those various companies as well as reviews of their products. Some shiitake mushroom "plugs" (which is what the wooden dowels inoculated with mushroom spawn are called) are better suited for colder climates than others so be mindful of the highest and lowest temperatures in your area before ordering.
Drill holes about 2″ inches deep in a diamond pattern along your log. You will want your holes to be 3-5″ inches apart and in 4-5 rows depending on the size of your log. Then hammer in one dowel per hole. This is easy right?! Make sure the dowel sinks into the hole a bit and is not sticking out. If you need to, use a small punch to hammer the dowel into the log. The last step is to wax the top of each dowel-filled hole so that they are well sealed. You can also wax the ends of the log, but multiple sources have noted that it is not necessary. It is recommended that you use “cheese wax” or beeswax. Most mushroom suppliers also sell cheese wax for your convenience. Since I have an abundance of beeswax from my hives, I didn’t see a need to spend money on the cheese wax, although it is only about $8.00 a pound.
Next, simply stack the logs so that they are not touching the soil. Soil can contaminate your logs with other types of mushrooms. Considering all the time you just spent drilling holes and pounding plugs into these precious shiitake logs, I doubt you would want to risk it by setting them directly on the ground. Think about setting up a little rack or even some other logs for your shiitake logs to rest on.
Now let's tap our toes impatiently as we wait six months to a year for our mushrooms to "fruit", or produce mushrooms. It is going to be awhile. After you inoculate, you should water the logs 2-3 times a week to maintain the moisture level in the wood. After a log is taken over by the mycelium (mushroomyness), they will start to fruit. Once the mycelium is established, you can also force fruit the logs by completely soaking them in water for 12 to 24 hours every five weeks. Your awesome new shiitake logs should produce for 4-6 years before they need to be replaced. But, really, if you start a new small batch every year or two, you will always have producing logs.