Growing Oyster Mushrooms
Oyster Mushroom Cultivation
Growing Oyster mushrooms is a very popular choice for home cultivation, firstly because they’re relatively quick and easy to grow, but also thanks to their delicious flavour and versatility. There are several varieties of Oyster mushrooms, the most commonly grown being Blue/Grey, King, Yellow and Pink Oysters, each with their own unique characteristics and requirements. In this guide, we will try to walk you through the cultivation process, including the differences you might find between the varieties.
Popular Varieties
Blue/Grey Oyster Mushrooms (Pleurotus ostreatus var. columbinus)
Characteristics: Blue Oyster mushrooms have a striking blue-grey colour and a mild, earthy flavour.
Growth Requirements: Blue Oysters prefer temperatures ranging from 55°F to 75°F (13°C to 24°C).
King Oyster Mushrooms (Pleurotus eryngii)
Characteristics: King Oyster mushrooms have a thick, meaty stem and a mild, nutty flavour.
Growth Requirements: King Oysters thrive in temperatures between 65°F to 75°F (18°C to 24°C).
Yellow Oyster Mushrooms (Pleurotus citrinopileatus)
Characteristics: Yellow Oyster mushrooms have vibrant yellow caps and a delicate, slightly sweet taste.
Growth Requirements: Yellow Oysters prefer temperatures from 65°F to 75°F (18°C to 24°C).
Pink Oyster Mushrooms (Pleurotus djamor)
Characteristics: Pink Oyster mushrooms boast a vibrant pink colour and a slightly peppery flavour.
Growth Requirements: Pink Oysters prefer warmer temperatures between 70°F to 80°F (21°C to 27°C).
Unlike most others, Pink Oyster Liquid culture should not be stored in a fridge.
Growing Supplies
Spawn Types
Oyster mushrooms are generally very forgiving when it comes to what you can grow them on, but most growers will use Rye, Millet, or Wheat for spawn. However, sawdust spawn, made by inoculating sterilised sawdust, also works well.
Substrates
We’ve heard it said that if you chuck a bag of Oyster grain spawn into your dustbin you’ll get oysters pushing the bin lid open before you know it. While that’s a slight exaggeration, Oysters can be grown on various different substrates. Wheat or barley straw is popular, easily found and cheap. Hardwood sawdust is also very good and can be mixed with other substrates for added nutrition. If you’re looking for cheap substrates and have a coffee shop nearby (who doesn’t?) fresh coffee grounds are rich in nutrients and readily available and can be mixed with other substrate materials. Believe it or not, cardboard can also be used as it provides structure and can be mixed with other substrates.
Growing Containers
Oyster mushrooms can be grown in either grow bags or plastic buckets. Grow bags are popular and companies such as Unicorn produce over-size bags which are especially suited to growing Oyster mushrooms. For larger grows, plastic buckets (with sealable lids) are very popular. These will have holes drilled into the sides through which your Oyster mushrooms can fruit. Oyster mushrooms can be top-fruited, for example if you cut the top of a bag, but grow much better if side-fruited, either via holes cut into bags or drilled into buckets.
Growing Oyster Mushrooms
As with all mushrooms, growing Oyster mushrooms is done in steps, starting with inoculating the grain or spawn material, moving to incubation and then fruiting and harvesting.
Inoculation and Incubation
Inoculation of your spawn material is straightforward and done in the same manner as any other mushroom type. As always, care must be taken to ensure sterility during the process. Your inoculated spawn should then be placed in a warm, dark location at between 22°C and 26° for 1-2 weeks until it has been fully colonised by mycelium. To reduce the risk of contamination in the next stage, once you think your spawn is fully colonised, always leave it another 5-7 days to consolidate and ensure the centre of the spawn is colonised.
Substrate preparation
Depending on your chosen substrate type it will need to be either sterilised or pasteurised – our advice is to read up on your chosen substrate type to ensure it is correctly prepared.
Mixing Spawn and Substrate
Your spawn and substrate need to be thoroughly mixed to ensure even colonisation. This needs to be done rapidly, ideally in a room with ‘still air’, with doors and windows closed, heating off and which hasn’t been vacuumed in at least 2-3 hours. Once you are satisfied, seal your container and place it into incubation conditions again until the mix is fully colonised with mycelium.
Fruiting – Temperature and Humidity
Once your substrate block is fully colonised it can be brought into fruiting condition. Your container should be moved to a location where it will receive indirect light – not direct sunlight. The temperature and humidity needs to be controlled and maintained carefully. The temperature and humidity ranges for different Oyster strains are shown below and if followed, you’ll soon be growing Oyster mushrooms!
Blue Oyster: Temperature – 16°C to 23°C, Humidity – 85% to 90%
King Oyster: Temperature – 18°C to 23°C, Humidity – 85% to 90%
Yellow Oyster: Temperature – 18°C to 23°C, Humidity – 85% to 90%
Pink Oyster: Temperature – 22°C to 26°C, Humidity – 90% to 95%
Harvesting Oyster Mushrooms
Oyster mushrooms are ready to harvest when the mushrooms caps fully open but before they flatten out. Twist or cut mushrooms at the base to harvest. Remember to keep humidity levels high and provide proper air circulation to prevent mould growth.
Possible Problems?
Growing Oyster mushrooms is relatively easy compared to some other mushroom varieties but growers still need to take care during cultivation to avoid problems. Here are some of the problems mushroom growers can face throughout the cultivation process.
Specific Oyster mushroom issues
Yellow Oyster Mushrooms: Yellow Oyster mushrooms are sensitive to light exposure and may exhibit phototropic behaviour, growing towards light sources. Growers need to ensure even light distribution to prevent uneven growth.
Pink Oyster Mushrooms: Pink Oyster mushrooms are prone to drying out, especially in low humidity environments. Adequate moisture levels are essential for successful cultivation.
General Issues
Contamination: Contamination by competing fungi or bacteria is a significant concern in mushroom cultivation. This can occur during substrate preparation, inoculation, or fruiting stages.
Poor fruiting: Failure to produce mushrooms can result from various factors, including inadequate humidity, improper temperature, lack of air exchange, or substrate issues.
Mould growth: mould can develop on the substrate or mushrooms themselves, typically due to excessive humidity, poor ventilation, or contamination.
Slow growth: Slow colonisation of the substrate or failure to colonise altogether often stems from poor quality liquid culture, incorrect substrate preparation, or environmental factors.
Small or deformed caps: Improper environmental conditions, such as low humidity or insufficient air circulation, can lead to small mushroom size or irregular cap formation.
This is a mushroom growing guide specifically for Oyster mushrooms, but we have growing guides for other mushroom species here on our mushroom growing guides page.