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Shiitake mushrooms cultivated on logs can exhibit remarkable productivity. High-quality logs have the potential to yield fruitful harvests for a period of up to 8 years. The process of inoculating logs is straightforward and easy to follow. The key to maintaining and managing the logs lies in effectively regulating moisture levels and patience. However, there are some other factors that are also worth noticing, like using other growing mediums and growing conditions, therefore let’s dive into the world of growing shiitake mushrooms at home.
What are Shiitake Mushrooms Exactly?
Originating from East Asia, Shiitake Mushrooms (scientifically known as Lentinula edodes) are delectable fungi that have become synonymous with Japanese cuisine. Although approximately 83% of the world’s Shiitakes are produced in Japan, they are cultivated across the globe.
Shiitake mushrooms, along with the broader Lentinula genus, fall under the classification of agaric mushrooms. These mushrooms are characterized by their distinct mushroom cap, separate from the stalk, and gills located beneath the cap. In terms of appearance, they range in color from tan to dark brown, with mushroom caps growing to a diameter of 2-4 inches (5-10cm). The name “Shiitake” derives from the Japanese phrase “mushroom of the shii” (referring to the oak tree), as the species is commonly found growing on oak or similar hardwood trees in the wild.
Growing Indoors vs Outdoors?
To begin, it is important to determine the location for your mushroom cultivation, as there is a noticeable distinction between indoor and outdoor cultivation of shiitake mushrooms.
Growers typically cultivate commercial shiitake mushrooms indoors by using large growing bags filled with supplemented sawdust substrate within a sophisticated fruiting chamber. This setup involves advanced temperature controls and air ventilation systems, requiring substantial resources and investment.
For most hobbyists or first-time growers, using a shiitake log is a more practical approach. Mushroom logs require a longer-term commitment, with an inoculation period ranging from 6 to 12 months. Although, cultivating shiitake logs demands minimal maintenance, making it a worthwhile investment that rewards patience.
The Logs
To achieve optimal results, it is recommended to cut healthy, living trees during their dormant season and let them rest for a minimum of 2 weeks before inoculation. This resting period allows the tree’s defense system to weaken. To prevent the logs from drying out, it is important to store them at a low height above the ground (without touching the soil or leaf layer), away from direct sunlight and wind, while still allowing them to receive natural rainfall.
While logs can be rested for a period longer than 2 weeks before inoculation, it should be noted that there is an increased risk of contamination and loss of vital moisture in the logs if they are rested for more than 8 weeks.
To produce a yearly yield of 5 to 10 pounds (2.2 to 4.5 kg) of mushrooms over a period of four to six years, you will need approximately 12 to 15 logs. These logs should be free from disease and damage, with the bark intact. We prefer using freshly cut white oak logs for shiitake cultivation, with lengths ranging from 3 to 5 feet (0.9 to 1.5 meters) and diameters of 6 to 8 inches (15 to 20 centimeters).
Find out how to grow mushrooms on a log here.
The Spawn
Once you have acquired the logs, it is time to obtain mushroom spawn, which serves as the seed to initiate fungal growth. The spawn usually comes in the form of short dowels infused with the fungus, packaged in jars or plastic bags. When inspecting the spawn, ensure that it is covered with a pulpy white and tan material, avoiding any dried-out or brown specimens. Your supplier will provide recommendations on the most suitable strain based on your location and level of experience.
Shiitake spawn is available in three varieties: cold strain, warm strain, and wide range. These strains differ in their fruiting patterns and preferred conditions for producing mushrooms. For beginners, the wide range strain is generally recommended. It is important to inform your supplier about the dimensions of your logs and the quantity you will be using to ensure you have enough spawn for your project. Keep the spawn refrigerated until shortly before its intended use.
Inoculating Logs
Once you have obtained your freshly cut logs (preferably 4 feet long), you can begin preparing them for inoculation. Utilize a reliable power drill equipped with a specialized drill bit that removes wood shavings as it bores. Drill holes in a row, approximately one inch deep and spaced around 2-3 inches apart. It is crucial to sterilize the drill bit beforehand to avoid introducing any pathogens to the mushroom logs. Start a second row with staggered holes positioned between the original ones. This will create a diamond pattern, maximizing the use of space. Repeat the process, drilling holes across the entire length of the log.
After the holes have been drilled, you are ready to insert shiitake mushroom plug spawn or sawdust spawn. If using plugs, simply place each plug into a hole and seal it with wax. If using inoculated sawdust, employ an inoculation tool to insert the sawdust into the holes. By sealing the plug spawn with wax, the mycelium will have a better opportunity to colonize the entire log, while the logs can retain their moisture content effectively. Whenever possible, opt for a soft wax, as it allows young fungi to penetrate it more easily.
Using pre-made plugs is often the simplest method for novice mushroom growers. These plugs are already filled with the spawn of the particular type of shiitake mushrooms you want, and a light tap will guarantee that they are firmly planted in their proper locations. If there is any excess plug remaining, you can use an angle grinder to cleanly remove it before applying a wax cap.
Inoculating Sawdust
Another option available to growers is the use of sawdust as a substrate instead of logs. Once you have your pasteurized substrate ready, thoroughly mix it with inoculated sawdust spawn to ensure proper distribution.
Before mixing, make sure to properly sterilize the container and any tools involved to maintain a sterile environment. At this stage, wearing gloves or having meticulously washed hands is essential.
Once the substrate has cooled down after pasteurization, incorporate the sawdust spawn into it, aiming to break the spawn into small-sized pieces for more even distribution within the substrate. Mix the ingredients thoroughly and pack the substrate into a sterile bag to facilitate colonization. Ensuring an even distribution of the spawn will expedite the colonization process. You can also use mushroom spawn in the form of plugs as an alternative method to inoculate the grow bags. However, the larger size of the plugs will result in a longer colonization time for the bags.
Fruiting Shiitake Mushrooms
When shiitake logs or sawdust bags have reached full colonization, they await the arrival of the rain to trigger mushroom growth. However, growers have the ability to simulate this process and encourage earlier fruiting, a practice known as “shocking” the shiitake logs or bags.
For those using shiitake logs, the recommended approach is to soak the fully colonized logs in cold water for approximately 24 hours. This can be done in various water sources such as a lake, bathtub, or water trough. It is important to ensure that the water is cool enough to avoid harming the spawn. Ideally, the water should be at room temperature or slightly chilled. Submerging the logs in water should prompt them to start producing mushrooms within 7-14 days.
A similar procedure is necessary for substrate-based mushroom cultivation. Place the shiitake mushroom grow bag in a bucket or sizable basin, cover it, and submerge it for two to three hours. However, it is important to avoid chlorinated water as it can harm the spores. Instead, opt for filtered water or water that has been left out for 24 hours to allow the chlorine gas to evaporate.
Harvest and Enjoy Your Shiitake Mushrooms!
Once the mushrooms appear and the characteristic gills form on the underside of the cap, it’s time to harvest them. Use a clean and sharp knife to cut the mushrooms off the log or substrate, taking care not to damage the growing medium. It is important to note that you can harvest shiitake mushrooms multiple times.
Congratulations! You have successfully cultivated your own shiitake mushrooms. Now, it’s time to savor the delightful and flavorful taste of shiitake and explore the countless culinary possibilities it offers. Let your creativity shine and enjoy!
