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Shiitake or Japanese forest mushroom is widely cultivated all over the world. It is unlikely that such mushrooms can be bought fresh - retail chains offer them only in dried form, and such semi-finished products must be soaked for a long time before cooking. Therefore, many amateurs have mastered the technology of growing shiitake mushrooms in their summer cottages, using stumps or logs for breeding mycelium.

How to grow shiitake mushrooms in the country

Growing mushrooms shiitake (Lentinula edodes) can be produced on logs or on the trunks of any deciduous tree, but oak or beech works best. You can test the hardiness of several strains. Thus, the strain of Japanese forest mushrooms "40 80" successfully overwintered in the open air at temperatures below minus 25 ° C. Harvesting and sowing with mycelium of Shiitake mushrooms of chumps is done in the same way as for oyster mushrooms. In conditions of daily fluctuations in temperature, shiitake bears fruit from May to late autumn better and more often than oyster mushroom.

The Chinese grow shiitake on long tree trunks. When laid horizontally on the ground, the stems look good and yield a good harvest of mushrooms. The trunks of trees with a diameter of 7-15 cm are sawn into pieces 100 cm long. An important condition for growing shiitake is that the water content in the wood is about 38-42%. If the moisture content of the wood is less, then the trunks are watered several days before the introduction of the mycelium.

How to grow shiitake in the country using stumps or logs? On the barrels, holes are drilled in a checkerboard pattern at a distance of 10 cm from each other along the length of the barrel and 7 cm between the rows of holes. The hole diameter is 12 mm and the depth is 40 mm. When growing shiitake on logs, the mycelium is introduced into the holes, the trunks are laid horizontally in high woodpiles for overgrowing with mycelium and covered with a film on top. In a greenhouse or in a shed, they incubate for at least a month at a temperature of + 20 ... + 26ᵒС.

The stem is considered mature for fruiting if it does not "ring" upon impact, the mycelium has captured the outer edge of the sapwood and white mycelium zones are visible on the cross section of the stem. Before soaking, the trunks are tapped with a hammer or hit with the butt on the ground. When spreading shiitake on logs at the dacha, the trunks are soaked in water with a temperature of + 13 ... + 18 ° C for 12 hours. During soaking, carbon dioxide, CO2, comes out of the trunks in the form of bubbles. When the bubbles cease to stand out, it means that the stems can be removed from the water. The moisture content of the wood reaches 60%. At higher humidity, the intensity of mushroom fruiting decreases.

To grow shiitake on stumps, the trunks are buried in the ground horizontally by half their diameter. In this case, it is easier to maintain the moisture content of the wood. If the plantation is located not in a greenhouse, but on the street, the plantation is covered with material that helps maintain the moisture required for fruiting. In 5-10 days after soaking, rudiments of shiitake mushrooms are formed in the places of the holes. Good quality mushrooms are formed at low temperatures (+ 10 ... + 16 ° С) and moderate air humidity (60-75%).

Daily fluctuations in temperature and humidity contribute to the formation of better quality mushrooms with dense pulp and an attractive appearance. The fruiting wave lasts 7-10 days.

After collecting the mushrooms of the first wave, the stems are kept for 2 months in drier and warmer conditions (+ 16 ... + 22 ° С). The moisture content of the wood during this period decreases to the level of 30-40%. The next waves of fruiting are achieved by repeating the procedure for induction of fruiting by soaking the stems. If you have mastered the technology of how to grow shiitake mushrooms, you can use the trunks in this way for 3-5 years. The total mass of mushrooms collected during this time is 15-20% of the mass of wood.

Here you can watch a video of growing shiitake mushrooms in your backyard:

Making Shiitake Substrate Blocks

The best material for future shiitake substrate mycelium is shredded oak branches, but other deciduous trees can be used as well. It is advisable to remove the leaves from the branches. The chopped branches should be used immediately.

The amount of substrate per substrate block is determined by the size of the plastic bag, in which the soaked substrate is heat-treated, and then, after sowing, the mycelium of the fungus develops there. It is the package that creates the necessary conditions for the development of the mycelium. The package determines the future shape of the substrate block and its dimensions.

When filling a polypropylene sleeve with a width of 25.5 cm, a block with a diameter of 16 cm, a height of 28 cm with a volume of 5 liters and a wet weight of 2.2 kg is obtained. When making a substrate from fresh branches of oak, willow or birch without leaves, add 200 ml of water per block. To increase the yield, 250 g of barley can be added to each block. In this case, the amount of water must be increased to 350 ml, and the mass of the block will be 2.8 kg.

For beginner mushroom growers, it is more convenient to use blocks weighing 1.3 kg with a volume of substrate in a block of 2.5 liters. So much fits into standard thin plastic packaging bags made of “rustling” low-pressure polyethylene, which can withstand heating up to +110 ° C.

Before growing shiitake, you need to make a substrate block. To do this, thoroughly mix chips, grain and water in the required proportions in a basin and pack the mixture into bags. Make cotton plugs with a diameter of 2-3 cm from a synthetic winterizer that was not used.To do this, roll tightly a strip of synthetic winterizer 30-40 cm long and 5-7 cm wide into a roll. Wrap the roll with threads. You can make such plugs from pure sterile cotton wool. Insert the stoppers into the neck of the substrate bags and tighten the bag around the stopper with hemp or polypropylene twine. Leave the bags with the substrate overnight so that the moisture of the added water is absorbed into the grain and distributed throughout the volume of the substrate in the bag.

Sterilize blocks with a substrate in a household autoclave at a temperature of +110 ° C for 3 hours. If an autoclave is not available, make fractional pasteurization of blocks with a substrate. After the substrate has cooled, inoculate (inoculate), if possible under sterile conditions. To do this, open the bags and quickly pour 100 g of grain mycelium into the neck of each bag. Close the bag with a stopper, pulling the string tightly around the throat of the bag. The bag must not contain any gaps or damage.

Inoculation of the mycelium into the substrate should be carried out in a clean, dust-free room or outdoors. Wipe a tablespoon and table surface with diluted "Whiteness" or other chlorine-containing preparation. Place the substrate bag on the table. With clean hands, knead the grain mycelium intended for sowing. Untie the wrapping of the substrate bag around the cork. Remove the stopper and place a tablespoon of grain mycelium on the substrate in a bag. Press the mycelium onto the surface with your fingers or a spoon. Insert the plug back and tie with twine. Form the substrate in a bag so that the substrate block can stand firmly on a horizontal surface. To do this, turn the bag over. Shake the substrate out of the corners of the bag, fold the corners along the bottom and glue them with a strip of tape.

Incubation of mushroom mycelium while growing shiitake

When the substrate blocks are held together by the overgrown mycelium, they will be of the same and regular shape.

For the development of the substrate block by the mycelium (for incubation of the mycelium), leave the package with the substrate in a warm place at a temperature of + 20 ... 26 ° C for 2 months or more. Through the film of the bag, you can follow the movement of the mycelium from top to bottom as the substrate is captured. The block should turn white, or white with brown spots, or brown. It is believed that the brown block is ready to bear fruit, but it is not.In the dark, the block absorbed by the shiitake mycelium remains white, and turns brown in the light. This is due to the color of the shiitake exudate. It is colorless in the dark and brown in the light. White blocks begin to bear fruit at the same time as brown ones.

The block may develop characteristic growths of the same color as the rest of the block, called popcorn mushroom growers. These are not yet the rudiments of fruiting bodies. With the help of these formations in nature, the shiitake repels the bark of the tree. The buds of fruiting bodies (primordia) are dense dark tubercles, which then develop into a mushroom cap.

Shiitake, unlike oyster mushroom, can form fruiting bodies of the correct shape at a high concentration of carbon dioxide - for example, when it is placed in a large plastic bag, not sealed tightly or with holes. To prevent the fruit bodies from tearing this bag and not rotting inside, it must be removed in time.

The block can easily be overgrown with mycelium for growing shiitake trees in a shady area of ​​the garden. The timing will change, but the process of overgrowing will not stop and it will be better if the package with the block is placed vertically, with a cotton stopper up. But in the open space, you have to turn the blocks over so that the rain does not wet the cork, or cover them from above.

Growing shiitake mushrooms in a greenhouse (with video)

Remove the plastic bags from the substrate blocks ready for fruiting and wash the blocks under running cold water. For shiitake blocks, the bathing procedure is useful for initiating fruiting - in nature, mushrooms begin to grow actively with the onset of the rainy season. Place the substrate blocks in the place of their future fruiting on the ground or on shelves.

If the units are installed indoors, it is necessary to create a suitable climate there. The optimum temperature is + 15 ... + 18 ° С. The relative humidity should be between 80 and 90%. In dry weather, block irrigation or water spraying can be used, but for indoor use an ultrasonic humidifier, a so-called fog or "cold steam" maker, is best. Humidifying devices can be switched on using a daily timer. For normal fruiting, shiitake needs lighting for 8-12 hours a day. Light doesn't have to hit all the mushrooms. At least one side of the substrate block must be illuminated.

In autumn, the air humidity is optimal in any shady spot in the garden. For fruiting shiitake blocks in the garden in summer, set them in the shade, in a cool place surrounded by plants. In the open air, in dry weather, water blocks and fruit bodies with water.

Shiitake blocks bear fruit well in a regular vegetable greenhouse, especially when surrounded by plants. A dedicated shiitake greenhouse can be built in the shade or protected from the sun with an opaque roof and south side wall. In order for the mushrooms to appear in the dry season in spring and summer, you can dig a shallow rectangular hole, overlay it with turf and cover with frames tightened with any cheap non-woven material to cover the beds.

Intact blocks with a dense brown crust can be made to bear fruit even on the surface of the water. Typically, these blocks are fairly dry and lightweight. For the formation of mushroom rudiments, the block must be placed in a puddle from the rain, on the surface of the water in a pool or in a barrel. After about a week, rudiments of fruiting bodies are formed on the wet side of the block. After that, the block must be turned over and after 7-10 days high-quality fruiting bodies are formed on its surface.

After the end of the first or next wave of shiitake fruiting in the garden or greenhouse, estimate the mass of the blocks. If they have lost a lot of weight, they should be soaked. To do this, pierce the blocks with a sharp knife in several places through and through, but so as not to break the block.

Immerse them in containers with water, pressing with a heavy shield, and keep them under water for 12-16 hours.

Soaking will accelerate the onset of the next fruiting wave and restore block mass.

Watch a video of growing shiitake in a garden greenhouse:

How to grow shiitake with sterile technology

Rigid sterilization in autoclaves is carried out at a pressure of 1.1 atm for 2 hours. The moisture content of the substrate is 45-65%. Sterilization of the substrate leads not only to the death of the entire microflora, but also increases the availability of the lignocellulose complex for enzymatic decomposition by the mycelium of fungi. This increases the yield of the mushrooms. After the death of microflora, the risk of infection by bacteria or molds greatly increases.

Pressure sterilization is carried out in special autoclaves. Pass-through autoclaves are convenient. In this case, the containers with the substrate are loaded from the dirty area, and the unloading is carried out into the clean area. The containers with the substrate are not placed close to each other in the autoclave, but at a short distance from each other so that air can circulate between them. This arrangement will provide an even distribution of steam and heating of the substrate and will significantly reduce the sterilization time. The substrate to be sterilized must be moistened to the required level. Substrate bags or jars must be opened or closed leaks. After increasing the overpressure in the autoclave to 1 atm, it is necessary to purge with steam in order to release air from the autoclave - open the valve to release steam for 10 minutes with the heater operating. It is very good to have a pressure gauge and a temperature sensor in the autoclave chamber. With an overpressure of 1 atm, the temperature in the chamber should reach +120 ° C. For complete sterilization of the contents of the autoclave, it is sufficient to maintain these parameters from 1 to 3 hours, depending on the mass of the substrate. It is permissible to heat up to +110 ° C. If sterilized for too long, the substrate becomes darker and its odor changes. It can become toxic to the mycelium of the fungus.

When the autoclave is turned off, the pressure and temperature in the chamber begin to drop slowly. Ideally, this should create a vacuum in the chamber. If the autoclave does not hold a vacuum, for example, when the valve is open, then when it cools down, it sucks in cold outside air. Autoclave with a pressure swing of +1 atm. up to -1 atm (vacuum that is created during its cooling), provides a good quality of sterilization, because with such a pressure drop (2 atm), biological structures are more actively destroyed. Before opening the autoclave, equalize the pressure by letting outside air into the chamber through a sterile cotton filter. For unloading, open the lid of the autoclave of the sterilizer. The substrate is still hot in the containers. If the autoclave is not through passage and its unloading is carried out in a dirty area, then it is better to unload the substrate hot and place it for cooling in a sterile box under UV lamps.

Substrate inoculation is carried out in a sterile box. By sterile technology on a wood substrate enriched with nitrogen additives, the yield of oyster mushrooms reaches 100% of the dry mass of the substrate, or 50% of the wet mass of the substrate.

Growing shiitake using an autoclave

The shiitake farm produces 1 ton of mushrooms per month. The composition of the substrate is dry oak sawdust (90%) and rye grain (10%). The components are moistened with water on a clean floor up to 60%, 1% gypsum is added and packed in polypropylene bags. To increase air permeability, replace 10% of the sawdust with oak or alder chips. The bags with the substrate are folded into metal baskets and sterilized in autoclaves at elevated pressure for 2.5 hours. After cooling, the bags are removed in a clean sterile area and 100 g of shiitake mycelium are poured into each bag. The sowing rate is 4%. The block weight is 2.5 kg. The bags are closed with cotton stoppers.

Sterile conditions are stored in the bag until the end of incubation. The substrate blocks are incubated in chambers without fresh air for almost two months at an air temperature of + 22 ... + 24 ° C. During incubation, the substrate first turns white, and then begins to acquire a brown color. The substrate is taken out for fruiting when more than half of the block turns brown.The blocks are freed from the film and placed in the fruiting chambers. There are 30,000 shiitake blocks in 8 fruiting chambers. The air handling unit provides humidification and heating of the air. The lighting in the cells is low, about 100 lux. For good fruiting of shiitake, warm (not lower than +16 ° C) and humid (80-90%) air in the amount of 7500 m3 / h is supplied to the chambers. The fruiting cycle of a shiitake with three waves is 120 days, and taking into account incubation, the entire cultivation cycle takes 180 days, or 24 weeks.

Shiitake primordia (mushroom rudiments) are large. They emerge from cracks in the outer crust of the substrate block. Primordia are formed over the entire surface of the block. The quality of the mushrooms improves with a decrease in the night air temperature in the fruiting chamber.

The initiation of the first wave of fruiting takes place better with external short-term watering in blocks with water for several days. This watering is needed in order to wash off the exudate formed during the incubation of the blocks under the film. The initiation of the second and subsequent waves of fruiting is carried out by soaking the blocks in water until their original mass is restored. To do this, the blocks are pierced through with skewers and in a special bath they are poured with water at room temperature overnight. In the morning they are returned to the fruiting chamber. During the collection of mushrooms, the caps are cut off, leaving hemp, which are removed from the block by twisting after a few days.

New technology for growing shiitake with steam heat treatment

One of the new technologies for growing shiitake is the method of heat treatment with steam. The substrate shop with an area of ​​100 m2 includes a small compartment for storing raw materials, a room with a substrate machine and a clean area where the finished substrate is inoculated. A 35 kW electric steam generator provides steam for heat treatment of the substrate.

Substrate composition: oak sawdust 70%, sunflower husk 20% and wheat bran 10%. The components of the substrate in dry form are loaded into a substrate machine (rotating barrel), the required amount of water is added and steamed for 4 hours at a temperature of + 90 ... + 100 ° C. All the while steaming, the barrel rotates to mix the substrate. The moisture content of the finished substrate should be approximately 60%.

The unloading of the finished substrate takes place with the help of an auger into a clean area. A laminar flow cabinet with purified filtered air supply is installed in the unloading area. The substrate is poured into small polyethylene bags (packaging) and at the same time the mycelium is added manually in the amount of 2% of the substrate weight. The inoculated bags are transferred through the airlock to the room, where workers shake up the bags to evenly distribute the mycelium in the substrate. Then the bags are transported on a trolley to the incubation chambers.

Three chambers with a total area of ​​500 m2 were allocated for incubation with a total load of 22,000 blocks of 1.8 kg each (a total of 40 tons of sub-118 strata). To accommodate the substrate, 7-tier racks made of timber with PVC-insulated metal mesh are used. In incubation chambers, air humidity is not regulated. The incubation process lasts 2.5 months (10 weeks).

The bags with the substrate are placed on the racks at a short distance from each other. The air temperature is maintained so that the substrate does not cool below +26 ° C.

On the 20th day, white bumps ("popcorn") appear on the surface of the substrate. Then the blocks start to brown. On the 70th day, the rudiments of fruiting bodies are formed, the film is removed from the blocks and transferred to the fruiting chamber.

For fruiting, three chambers are used with a total load of 10,000 blocks, or a total of 18 tons of substrate. The substrate is placed on 6-tier timber racks. The chambers are equipped with microclimate control systems. To moisten the blocks, drip irrigation with water is used. Additionally, steam from an electric steam generator is used to humidify the air. The optimum fruiting temperature for shiitake is + 14 ... + 16 ° С. The fruiting period on the first wave is 8-10 days.

In the period between the waves, the temperature in the chamber is raised by 4 degrees and the spraying of water is stopped to tighten the external damage to the block after collecting the mushrooms. The blocks are "resting" for 3 weeks. After "rest" for several days, the blocks are plentifully irrigated with water to restore their original mass. The air temperature is reduced, and the air humidity is brought to 90-95%. The yield on the first two waves of fruiting is 13-15%.