Oyster Mushroom Grows Almost Anywhere

In short: Oyster mushrooms grow at 15 to 25 °C, either in bags of pasteurised straw or on fresh hardwood logs. A straw bag fruits for about 3 to 4 months and gives roughly 2 to 4 kg per spawn package. Logs crop once a year, for 3 years on soft wood and up to 5 years on hard wood.

Oyster mushroom (lat. Pleurotus ostreatus) is an edible wood-decaying fungus belonging to the Pleurotaceae family (lat. Pleurotaceae). Its original homeland is China, but it is currently distributed worldwide, growing in temperate zones as well as in subtropical forests.

What oyster mushrooms actually look like

The caps of oyster mushrooms resemble larger oysters in both shape and colour. This similarity to oysters gave this mushroom its species name. When young, the caps of oyster mushrooms are convex with inrolled margins, later becoming fan-shaped, reaching widths of 5 - 25 cm. The margin becomes sharp. The colouring of the caps is variable, from whitish, grey-blue, grey-brown to brown.

The colouring depends on growing conditions, air humidity and the specific cultivar. The caps grow in clusters, rows or layers above each other, similar to most other oyster mushrooms. Individual clusters can reach a weight of several kilograms. The gills of oyster mushrooms are low, soft and dense, decurrent on the stem. They are dichotomously branched near the stem. Young gills are white in colour, becoming grey with age.

The stem of this mushroom is very short, only 1 - 4 cm long and approximately 1 - 3 cm thick. The stem is very tough, white, later becoming greyish. The flesh is pure white, very elastic and juicy. The colour does not change after cutting. The taste of oyster mushrooms is sweetish, the aroma is pleasantly mushroomy. The spores of oyster mushrooms are colourless, cylindrical and smooth.

Oyster mushrooms grow in nature from late summer until winter. In mild winters, they can often be found in spring on living or dead trunks of deciduous trees. They thrive best on beeches, willows, walnuts, rowans, birches and poplars. Currently, it is one of the most abundantly cultivated mushrooms in both home and laboratory conditions. The largest producers of oyster mushrooms from laboratory conditions are currently China, the Philippines, Thailand, Pakistan, Nigeria and the USA.

In the past, research on oyster mushroom cultivation was also conducted in the Czech Republic. A major boom occurred after 1982, when large cultivation facilities were established here. After November 1989, however, the facilities began to decline due to the opening of borders and imports of oyster mushrooms from other countries. Oyster mushroom is the third most commonly cultivated mushroom in the world.

Types of oyster mushrooms

Other types of oyster mushrooms, besides the oyster mushroom, include phoenix oyster (lat. Pleurotus pulmonarius), branched oyster (lat. Pleurotus cornucopiae), veiled oyster (lat. Pleurotus calyptratus), oak oyster (lat. Pleurotus dryinus), king oyster mushroom (lat. Pleurotus eryngii) and pink oyster mushroom (lat. Pleurotus djamour).

• The lung oyster mushroom is considered the sister of the oyster mushroom. They grow at the same time and in the same places. Its cap is 5 - 12 cm wide, domed, often fan-shaped. The surface is grooved towards the edge and sometimes torn. Young mushrooms are whitish in color, older ones become dark brown. Multiple caps can grow from one stem. The gills are very tall, and the flesh is white. The lung oyster mushroom has versatile uses.

• The cup-shaped oyster mushroom has a cap 4 - 10 cm wide. When young, the cap is domed with an inrolled edge; in maturity it becomes flat, depressed in the center or funnel-shaped. The cap color can be whitish, pale yellow or brown. The cap surface is smooth and bare. The stem is long and wide, central or eccentric. The spore print is white with a purple tint. You can find the cup-shaped oyster mushroom from spring to autumn on trunks of deciduous trees, most commonly oaks and beeches. It has spread throughout the temperate zone of the northern hemisphere. It is suitable for soups and pickling in vinegar.

• The veiled oyster mushroom is relatively rare. It grows on dead aspen wood. This oyster mushroom's cap is dome-shaped and attached sideways to the trunk. It reaches 3 - 9 cm in diameter. The cap surface is smooth; in old age, remnants of the veil remain on the edge. The cap is beige or light brownish-gray in color. It grows from July to October. It occurs only in Europe. Although the veiled oyster mushroom is edible, it is not collected due to its very rare occurrence.

• The oak oyster mushroom is misleading by its species name, as it can be found more often on apple trees than on oaks. Its cap has a diameter of 4 - 15 cm, with a scaly surface and whitish to grayish color. The oak oyster mushroom grows on trunks and stumps from August to November. This species of oyster mushroom is also edible, but due to its toughness, it is not very popular.

• The branched oyster mushroom is sometimes nicknamed the royal oyster mushroom. This species can be cultivated at home on straw substrate. In nature, it occurs rarely. Its cap is flatter, hemispherical. The distinguishing feature is a thin inrolled edge. The color ranges from whitish, brownish to grayish. Younger fruiting bodies are felty to the touch; in dry environments, the caps may crack. In nature, this mushroom is rare. With luck, you can find it from spring to autumn on the roots of hogweed and on field eryngo.

• The pink oyster mushroom originates from Southeast Asia. It is very tasty and also very healthy. Beneficial effects against lifestyle diseases have been proven; thanks to its glucan content, it increases the body's resistance to viral infections and prevents or slows the growth of certain types of malignant tumors. It requires higher temperatures for growth than other oyster mushroom species.

In our e-shop, you can grow oyster mushrooms in your own garden in beige and grey varieties, as well as pearl oyster mushrooms and pink oyster mushrooms. Oyster mushrooms are cultivated using two methods - in bags on straw and on wooden logs.

Growing Oyster Mushrooms in Straw Bags

Growing oyster mushrooms in straw bags is very simple and even beginners can handle it. This method allows you to grow oyster mushrooms all year round.

1.) First, prepare the straw and sterilize it with boiling water to eliminate bacteria, mold, and other fungi. Then let the straw cool down and repeat the sterilization process once more.

2.) You can start the inoculation itself only when the straw has cooled down to below 30°C. Straw inoculation is carried out by alternately placing straw and crumbled inoculation substrate into a large bag measuring approximately 50 x 100 cm. One package of inoculation substrate is sufficient for approximately 15 - 20 kg of moistened straw. Close the filled bag, preferably tie it shut.

3.) Using a sharp object, cut 3 - 5 cm slits into the bag, making approximately 10 slits per bag in total. In environments with low air humidity, make fewer slits to prevent the straw from drying out. Place the bag with inoculated straw in partial shade so that direct sunlight doesn't hit it.

4.) Oyster mushrooms thrive best at temperatures of 15 - 25°C. The higher the temperature you provide for the oyster mushrooms, the faster they will grow, but this will also deplete the nutrients in the straw more quickly. If you want to slow down the growth rate of new fruiting bodies, move the straw bag to a cooler location. Under these conditions, oyster mushrooms produce fruit for approximately 3 - 4 months, after which the nutrients are depleted and you need to establish a new culture. From one package of inoculation substrate, you can grow approximately 2 - 4 kg of oyster mushrooms.

Growing Oyster Mushrooms on Wood

The second method of growing oyster mushrooms is cultivation on wooden logs. When using this cultivation method, you'll get a harvest only once a year, but for several consecutive years.

1.) In the first year, you establish the oyster mushrooms in the log, and in subsequent years you simply harvest the fruiting bodies. For oyster mushrooms to grow well, it's important to select the right wood. Fresh wood from deciduous trees is used, which should be felled during the dormant season. The most suitable species are poplar, birch, alder, oak, beech, hornbeam, or willow. Wood from fruit trees is also usable, with the exception of apple and walnut. Ideally, no more than 1 - 2 months should pass from the tree being felled so that the wood still retains its natural moisture.

2.) For cultivation, use trunks and branches with a diameter of 15 cm and length of 30 - 40 cm. Inoculation with oyster mushroom spawn must be done immediately after cutting into logs. Drill 5 - 10 holes in each log, 1.5 - 2 cm wide and 2 - 3 cm deep. Don't drill larger holes, as the spawn needs to be in the tightest possible contact with the wood to prevent it from drying out before it starts to grow. If you're setting up multiple logs, prepare a pit approximately 2 m deep and 1 m wide.

3.) Cover the bottom of the pit with polyethylene film and spread a thin layer of spawn under each log. Always stack 2 - 3 logs on top of each other. Nail a 1 - 2 cm thick wood disc to the top log. After placing the logs, cover the pit with planks and spread a film over them, which should be further covered with branches and soil. This method provides the oyster mushroom spawn with stable temperature and sufficient moisture. During hot summer days, occasionally spray the roof with water.

4.) You can expect fruiting bodies when night temperatures drop below 10 - 12 °C. At this time, mow the grass around the logs and carefully uncover them, watering as needed. Harvest fruiting bodies the size of a child's palm, trying not to damage the bark of the logs. The fruiting period depends on the wood hardness - softwood produces for 3 years, hardwood for 5 years.

5.) A smaller number of logs can also be prepared in a cellar. Damp cellars with stable temperatures in the range of approximately 8 - 15 °C are suitable. Place a brick at the bottom of a thick plastic bag, pour 2 - 3 liters of water into it, and stack 2 - 3 logs on the brick, layering them with spawn. The film will protect the logs from drying out.

6.) The mycelium will grow through the log in approximately 4 months. Properly colonized logs are fused with mycelium and have white cotton-like oyster mushroom mycelium on their surface. Move the prepared logs outside to a damp, wind-free location, preferably under trees. At this location, dig holes 15 - 20 cm deep, spaced 40 - 50 cm apart. Place the logs in the prepared holes so that roughly half protrudes above ground. During warm and dry periods, water the logs once a week. Then just wait for the first fruiting bodies to start growing.

Medicinal Benefits of Oyster Mushrooms

Oyster mushrooms contain a specific ß-d-glucan (pleuran), which can activate the cellular immune system. Glucans from oyster mushrooms have antiviral and anti-inflammatory effects and contribute to lowering cholesterol. Another group of active substances found in oyster mushrooms are terpenes with antibiotic and anticancer activity.

Oyster mushroom fruiting bodies also contain lovastatin, which significantly reduces cholesterol from blood serum. Oyster mushrooms work against inflammatory, viral, bacterial and fungal diseases. They have a beneficial effect on treating hemorrhoids, varicose veins, leg ulcers, burns, eczema and skin allergies.

They have a preventive effect against cancer as well as against radioactive and UV radiation. Consuming oyster mushrooms is also recommended as prevention against heart disease. Include oyster mushrooms in your diet and prepare, for example, a soup.

Side effects may include intestinal problems, which can be caused by the small amount of arabitol contained in oyster mushrooms. In very rare cases, diarrhea may occur.