There are few mushrooms as iconic as The Shiitake.
And although growing shiitake mushrooms requires some specialized skills and tactics, it is still a strong favorite among cultivators- both professional and amateur alike. In fact, Shiitake is one of the most commonly cultivated mushrooms in the world. And for good reason. The Shiitake is a culinary delight, has a long shelf life, and when grown right, can produce bountiful yields.
There are a few different ways to grow shiitake.
Traditionally, Shiitake mushrooms were grown on hardwood logs and stumps, with pioneering methods developed in Japan many decades ago. The “soak and strike” method consisted of soaking inoculated hardwood logs followed by striking them with a hammer- causing the logs to fruit.
This method of growing shiitake outdoors on logs is still quite popular today, but most commercial and hobby cultivation is now done using hardwood sawdust fruiting blocks – allowing for more predictable and more profitable cultivation.
I just finished up with a successful Shiitake grow at home, and wanted to share the results with you- so that maybe you can try growing this mushroom as well.
But before we get into that, let’s see what this mushroom is all about!
The Shiitake Mushroom
Scientific Name: Lentinula edodesGeneral Description
Shiitake mushrooms will start to pin from large knots formed on the surface of the substrate, eventually developing into a more traditionally shaped cap and stem mushroom. The cap is dark to light brown and speckled with a rough white tissue, remnants of an earlier stage of growth. The stem is also quite rough, with a fibrous texture – appearing as if it was scraped with a fork. The cap size can vary greatly, from 1-5 inches, depending on the strain, growing conditions and time of harvest. The gills of the shiitake mushroom are serrated, and white in color.
Natural Habitat: Usually found on dead hardwood logs and stumps, most commonly shii, oak, maple and beech. Also found on poplar. Shiitake is sometimes found on living trees, but will only feed on dead tissue.
Difficulty of Cultivation: Medium to Difficult.
Agar: Shiitake mycelium grows quite vigorously on agar. It will often start off quite thin and whispy, rapidly becoming thicker, and eventually turning brown with age. This browning is not contamination, but rather a natural stage of growth. MEA works well for Shiitake.
Spawn Types: Shiitake grows well on both sawdust and grain. Grain is recommended for at least the first generation. Suitable grains are rye, sorghum, millet, or a combination of these.
Substrate Types: Shiitake grows on hardwood. Hardwood sawdust blocks work best. Low levels of supplementation with oat bran or wheat bran improves fruiting, but some say too much supplementation can cause odd looking fruits and lower yields. Some strains have also been developed which will grow on straw.
Shiitake Myceluium on Agar. This mycelium is still young, and has not yet browned.
Fruiting Containers: For indoor cultivation, use large autoclavable grow bags. Once the block has fully colonized, leave the block in the bag until it forms large knots and a brown outer crust. Cold shock, and remove from the bag entirely before fruiting. Can also be grown on hardwood logs for outdoor cultivation.
Yield: Anywhere from 1.5 to 3 lbs can be harvested from each 5 lb fruiting block over a number of flushes. Expect to yield anywhere from 0.75 – 1.0 lbs on the first flush. It is common to completely dry out the fruiting blocks for a 1-2 week resting period between flushes.
Harvest: Shiitake mushrooms can be harvested at range of different sizes. Many cultivators prefer to harvest the mushrooms when young. Allowing the mushrooms to grow larger, up to the point where the cap flattens, will increase the yields- although the quality of the fruit begins to diminish. You should definitely harvest shiitake before the spores are dropped.
Weakness: Shiitake fruiting blocks typically take much longer than oyster mushrooms in order to get to the fruiting stage from the time of inoculation. They also prefer a cold shock in order to initiate pinning. Shiitake requires a longer “resting period” between flushes, where the blocks are to be dried out before being re-soaked for a second flush.
Cooking: Shiitake mushrooms are certainly a favorite in the kitchen. Add to a whole variety of dishes, from soups to pastas and everything in between. Requires slightly longer cooking times than oyster species or typical button mushrooms.
The Specifics
Spawn Run:
Incubate grain spawn at room temperature or slightly above for about 3 weeks. Spawn should be shaken a couple times to increase the speed of colonization.
Initiate Pinning:
Cold shock the fruiting blocks at 3-5 deg C for 12-24 hours. Allow pins to form inside the bag, then remove the entire bag from the fruiting block and keep at 95-100% RH for 3-4 days.
Fruit Development:
Aim for 18 deg C for best results. Humidity should be around 80%. Shiitake will form normal looking fruits at elevated CO2 levels, making fresh air less of a concern than for oyster species.
A Recent Shiitake Grow
On May 5th I inoculated 4 supplemented sawdust fruiting blocks with about 2.5 lbs Shiitake Mushroom grain spawn. The blocks were allowed to colonize for about 7 weeks, and then put in the fruiting chamber. I ended up harvesting about 4 lbs from the 4 blocks on the first flush, and they are currently drying out for a resting period before the second flush.Substrates for Growing Shiitake
When it comes to suitable substrates, Shiitake is a little pickier than the easy-going oyster mushroom. Most strains will only grow well on hardwood, and even adding supplementation is a point of contention with some growers- who claim that high levels of supplementation will cause mutated fruits. I have tried this, and although I likely don’t have enough data for a true test, I find that supplementation with oat or bran flour still produces excellent results. In fact, for these blocks, I used the same recipe as I use for most other gourmet mushrooms I grown – hardwood fuel pellets, wheat bran and water. The bran is added at 1.25 cups per 5 lb fruiting block.Inoculation
These blocks were inoculated at a pretty high spawn rate, namely 2.5 lbs of spawn, evenly distributed between the 4 blocks, which equates to about 12.5% or about 0.625 lbs of spawn per bag. A high spawn rate like this not only increases the speed of colonization, but also acts to further “supplement” the blocks, since the grain is highly nutritious and can help to improve time-to-fruit and overall yield. This level of spawn rate is not always economical on a commercial scale, but for home growers, it can increase the chances of success. The grain spawn used was FreshCap Shiitake Spawn, which utilozes a high yielding and aggressive strain grown out on sorghum grain. This particular strain grows exceptionally well on hardwood- which is an important distinction, because there are strains that have been developed that will grow well on straw. Check out this video below for how I inoculated these blocks.
After inoculation, the blocks were set on a shelf in room temperature and normal lighting conditions, and left relatively undisturbed- other than periodic checking to monitor the progress of the colonization.