Shiitake mushrooms grown on logs can be highly productive. Good quality logs can fruit for up to 8 years. Inoculating logs is simple and straightforward. Maintaining and managing logs is a matter of moisture management and patience. Before you begin, please be sure you have good quality logs to make the best possible Shiitake growing experience. Follow the six steps below for inoculating and managing your Shiitake logs.
Follow the six steps below for inoculating and managing your Shiitake logs.
1. Cut the logs (3-8˝diameter x 36-40˝ length)
Healthy, living trees should be cut during the dormant season and rested a minimum of 2 weeks prior to inoculating. This allows time for the tree's defense system to die back. Protect the logs from drying out by storing them low to
the ground (but out of the soil and leaf layer), out of the sun and wind, and where they can receive natural rainfall. Logs can be rested until inoculation for longer than 2 weeks, however there is increased risk of contamination and
losing vital log moisture beyond 8 weeks.
NOTE: Logs can be cut to size for either the Drill-and-Fill Inoculation Method using standard log sizes (3-8" diameter x 36"-40" length) or the Totem Inoculation Method using larger diameter logs (6-12" diameter x 6" length).
2. Drill the holes
Drill the holes to a 1˝ depth following the diamond pattern (figure on right) for roughly 50 holes per log. Plug spawn requires 8.5mm (5/16˝) drill bit, and sawdust spawn typically requires 12.5mm (7/16˝) drill bit.
3. Inoculate and seal with wax
Plug spawn: Use a hammer and gently tap in one plug per hole so it is flush with the surface of the log. Seal each plug with melted wax or plug wax.
Break apart the spawn and inject it into each of the holes, typically with the use of an inoculation tool.
Thimble spawn: Push one thimble into each of the holes.
Pack spawn into the hole so it fills level to the bark. Wax the filled holes as the logs are inoculated to protect the spawn from drying out and reduce the risk of contamination. Thimble spawn does not need to be waxed. Be sure the hole is completely sealed. Waxing the ends of the logs is not necessary. Plug wax is an easy alternative to melting cheese wax and is easily applied using your finger as if you're applying lip balm over the end of the plug and hole opening. Hot wax is faster to apply and works better with sawdust spawn. Consider using wax daubers or the Okuda wax applicator. The flash point of cheese wax is 450°F. Do not overheat the wax! Turn down the heat if the wax begins to smoke.
4. Label the logs
Labeling logs with strain and date inoculated can be very helpful - especially as you continue to build up Shiitake log inventory. We use aluminum tags or other labels stapled into the ends of the logs.
5. Incubate logs and manage for moisture
Once inoculated, place your logs in a shaded area, protected from the sun and wind, low to the ground (we lay them on pallets or poles), and where they can receive natural rainfall. Maintaining moisture during this phase is the most critical step to Shiitake production success. We recommend your logs receive 1˝ of rain per week. If the weather is not cooperating, you may need to sprinkle your logs with a hose. Logs will begin producing mushrooms when spawn run is close to complete and the conditions for fruiting are ideal. This timing varies, so keep an eye on your logs. Once fruiting commences, they can be re-stacked into a different configuration to make harvest easier.
6. Harvest mushrooms
Monitor your logs as they fruit. Mushroom development can happen very quickly and it is best to pick them when the edges of the cap are still curled under. Over mature mushrooms do not store as long. Simply grab the mushroom, twist, and pull it off the log. Store your harvest in the refrigerator up to 14 days in a sealed storage container.
Easy to moderate.
Time to plant:
Typically spring, but throughout the growing season.
Time to fruiting:
Plug spawn: 9-18 months; sawdust and thimble spawn: 5-12 months (larger diameter logs take longer than smaller diameter logs).
When they fruit:
Spring through fall, depending on strain.
Logs grown on:
Hardwoods, ideally Oak species, Sugar Maple, and Ironwood.
Number of logs:
Depends on log size (ideal is 4-6˝ diameter x 36-40˝ long). Plug spawn: approximately 50 plugs per log. Sawdust spawn: 10-12 logs (2.5 lb. bag) or 20-25 logs (5.5 lb. bag). Thimble spawn: 12 logs per sheet of thimbles (50 thimbles per log).
Tan to brown capped with some degree of light colored scaling on cap, white stem and white gills.
Flavor and texture:
Strong, bold, garlic flavored, meaty texture.
Totem Inoculation Method
Place one cup of sawdust spawn in the bottom of a plastic garbage bag or large leaf bag. Set the log squarely on top of the spawn inside the bag (cut ends facing up and down). Sprinkle enough spawn on top of the log to cover it ⅛˝ to ¼˝ deep. Set another log on top of this and sprinkle more spawn. Cover and cap the top log with newspaper or brown paper bag and secure it onto the log (large rubber bands work well for this). You can also use a thin slice of log to cap the top. Close up the bag with a small rubber band leaving a slight opening for air exchange. Ideally they should be placed in an area with constant temperature between 60-80°F for 4-6 months.
Once the incubation phase is complete (you should see white fuzzy growth on the logs), remove the logs from the bag and place upright outdoors in a shady area where they are out of the wind and can receive natural rainfall. Watch your logs closely after several months of incubation. Oyster mushrooms fruit spontaneously and quickly and you do not want to miss them. Each of the oyster varieties differ in fruiting temperature. Consult the oyster chart for more information on when to expect your oyster to fruit and harvest as described in Step 6.
Force fruiting Shiitake logs (optional)
Force fruiting or "shocking" Shiitake logs is a strategy to achieve scheduled mushroom production. We recommend waiting to force fruit until early summer after the logs have naturally fruited and the weather is consistently warm. Shock Shiitake logs by submerging them in cold water (at least 20°F colder than air temperature) for 12-24 hours, then set them up for fruiting. Mushrooms develop 5-14 days after soaking depending on the temperature. The use of fruiting blankets or garden row covers to protect the crop is recommended. This process can be repeated on an 8-10 week rotation during the growing season. Note that the Shiitake strains WW70™, Miss Happiness™, Bellwether™, Snow Cap™, and Jupiter™ do not respond well to force fruiting.