For those wishing to venture into mushroom farming, we recommend growing oyster mushrooms. They have low startup costs and with proper management you may get a decent return within a very short space of time. Below we have a quick guide on how to get started on growing oyster mushrooms at home.
Below are a few terms we told you about in an earlier article and a few more to know when it comes to mushroom production.
Spawn – These are the mushroom “seedlings”
Spawning – Is the process of planting the mushroom
Substrate – Is the medium on which mushroom can be grown
Mycelium – It is the thread like part of a fungi (mushroom) that grows on the substrate or soil. It is referred to as hyphae. To put it in simplistic terms, mycelium is like the root of a plant and the mushroom and fungi are like the buds, leaves or fruits of a plant.
Mushroom growing house – After spawning, the substrate bags are kept in this room for development of the mycelium. Dark conditions are required as well as temps of about 24 0C in order to facilitate this process.
Mushroom fruiting – What we commonly see and refer to as “mushroom” is the actual fruit of the plant. Mushroom fruiting is process of the plant producing fruit.
Fruiting vessel – This describes the vessel used to grow the mushroom
To begin growing mushrooms you will need a mushroom growing house. Oyster mushrooms, like other mushrooms, are grown in a growing house but they may require a bit more humidity and fresh air than other varieties. Construction of the mushroom growing house should be simple and based on a very basic design. The dimensions depend on the number of substrate bags the grower can handle at any one time. The walls can be constructed out of bricks, poles, dagga, plastic or even thatch. Plastic or foam sheets may be used to line the walls in order to increase the relative humidity in the production house. The roof can be thatched with different kinds of materials like plastic, grass or even banana leaves. Air vents and windows on the upper side of walls are required for ventilation. The air vents and windows can also be used for lighting when needed to initiate fruiting. The mushroom growing house should provide optimum conditions for fruiting. Temperatures should also be carefully monitored and maintained.
Oyster mushrooms growing can be divvied up into a four-stage process
Step One – Substrate preparation
Things to consider when choosing a good substrate
- Easy availability
- High nutrient content for the mushrooms to grow
- Good aeration – not too compact and not too loose
- Good water holding capacity – not too dry and not too wet.
- Oyster mushrooms can be grown on a range of substrates such as: paper products, straw, leaves, agricultural waste, cotton residues and sawdust
- Chopped or shredded substrate is soaked in water overnight. After 24 hours, excess water is drained off and lime can be added. The substrate used must be pasteurised to eliminate contaminants or undesirable organisms. This can be achieved by boiling the substrate in a large pot or some type of drum for 60 minutes before transferring the substrate onto a plastic sheet to cool off to between 38-400 Immersion in boiling water is a cheap but efficient way of pasteurising the substrate. You may need a thermometer to determine when the substrate has cooled to the right temperature.
Step two – Spawning
- Good spawn is the key to successful mushroom production. You can pack the substrate into a tubular bag (clear plastic bags are often used for this purpose). Commence adding the spawn evenly layer by layer. Care should be taken not to pack the substrate too tightly or too loosely.
- There is a high risk of contamination during the planting process so it is paramount to keep a sterile environment. Tie the open end of the bag immediately after filling. Bags should be 10 – 20 kg capacity and preferably transparent. This makes it easy to check substrate colonisation and to detect contaminants. String the mouths of the bags and hang them onto racks if possible.
Step Three – Incubation
Spawned substrate bags are kept in a dark room at 240C. The spawned bags can also be covered with black plastic in the mushroom growing house. Incubation lasts between 14-40 days and full colonisation is evidenced by white mycelium covering the whole bag. During incubation, the mushroom mycelium grows to cover the whole substrate. Bags are ready for mushroom formation when the substrate appears white.
Step Four – Fruiting
- To initiate the formation of the mushroom bodies, expose the bags to light. Open the air vents or windows in the mushroom growing house to provide light and to initiate fruiting. When sufficient lighting hits the mycelium covered bags, then fruiting commences. After 24 hrs make long cuts at the top and bottom of the bags. Make more long cuts around the centre of the bag for more mushrooms to emerge. Mushrooms will start to form in 4 days and will be ready for harvesting in the next 2 to 3 days. Temperature should be maintained between 20-280C and an optimum humidity of 80-95%. For some, watering the floor with a can of water helps to maintain higher humidity levels.
- Harvesting is best done in the cooler hours of the day. That is, very early in the morning or late evening. Refrigerate the harvested mushrooms immediately after picking to preserve freshness. Some mushroom drying methods can also be used at this stage. Continue to harvest mushrooms until the substrate becomes colourless or whitish in appearance and has a soft feel to the touch. A good rule of thumb is that 10kg of substrate should give you a yield of about 10kg-20kg of mushrooms.
- After the substrate is pasteurized (heated to about 100 degrees and cooled), it is then mixed with spawn and packed into long, tubular shaped bags. Most people will use plastic bags. Holes are punched in the bags to allow the mycelium to breathe and the bags are hung up or set on racks in the growing rooms. After about 14 days, the mushrooms pop out through the holes and can be harvested. If straw is used as a growing medium, the substrate can be used as fertilizer after mushroom production is completed.
- To provide adequate moisture, water the substrate daily taking care not to over water.
- If temperatures rise to 300C, the door and air vents / windows may be opened at night to allow cool air to enter.
- Maintain high relative humidity by applying water on the floors and walls several times a day.
- Incomplete substrate colonisation delays fruiting. Ensure that the substrate is well colonized before initiating fruiting.
- The mushrooms will stay fresh for 3 to 6 days post harvest when kept in the refrigerator or in a cool area. They can also be dried using local methods of sun drying.
For more information on how you can get help from vaMudhumeni on how you too can get on the road to being an oyster mushroom farmer please contact us at