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Blue Oyster Mushroom Growing Profile

Close up of Blue Oyster Mushroom Growing from container


Blue Oyster Mushrooms are one of the most visually appealing fungi around, starting life a deep midnight blue before fading to a pale slate grey. Underneath the cap is no less stunning; layers of delicate, yet fleshy gills line the stem, all a brilliant white.

The name Blue Oyster derives from their resemblance to the sea molluscs, and they grow in the large, shelf-like formations typical of their genus, Pleurotus. These mushrooms are ideal for hobbyists, thanks to their ease and speed of growth (sometimes doubling in size daily), and they are also very forgiving towards the beginner or amateur grower!

A key requirement when growing Blue Oyster Mushrooms is near-constant fresh air exchange, in order to activate initial growth. This, plus their love of high humidity, means that they are perfect candidates for growing outdoors. Other benefits of being grown outdoors are the increased vibrancy in the colour of the caps which comes from exposure to indirect sunlight, and the fact that Blue Oyster Mushrooms tend to emit a large number of spores.

Aside from the visual attractiveness of Blue Oyster Mushrooms, their thick and meaty fruit lends itself to a wide range of culinary uses, with a bittersweet aroma similar to licorice or anise.

Habitat of Blue Oyster Mushrooms

Widespread in temperate and subtropical forests, Blue Oyster Mushrooms are usually found growing in shelf-like clusters on dead and decaying hardwood trees (beech trees in particular) during the milder seasons of spring and fall.

Their role as saprotrophs means that they digest and process the decaying organic matter, breaking up the deadwood and returning nutritious minerals to the ecosystem.
They are classed as a white-rot wood-decay fungus, meaning that they digest moist wood, leading to rot. However, as saprotrophs only attack dead wood, they are not causing any further damage to the ecosystem, as opposed to parasitic organisms which attack living trees and plants.

Unusually for a fungus, Blue Oysters are also carnivorous, consuming bacteria and minuscule worms called nematodes; these provide the fungus with nitrogen for growth.

Spawning Details for Blue Oyster Mushrooms

Temperatures for spawning should be approximately 77F or 26C. After spawning a high humidity of 90-100% is required, this is normally provided by the hydrated substrate. A spawn run takes between 14 to 21 days.

Blue Oyster Mushrooms are so easy to grow, they can be cultivated on practically anything: hay, straw, wood, sawdust, even coffee grains! One of the easiest and least-messy methods of spawning Blue Oyster Mushrooms is via cultivation in clear polyethylene bags packed with hay or straw, and with the spawn sown among the silage.

When using wood and straw cultivation, grain spawn is the best option, in particular rye grain. Grain spawn is made from sterilized grains that have been inoculated with live mycelium culture, lending a vast energy boost to the growing fungi, which will in turn lead to vibrant blues and large fruiting bodies. Plug spawn is another option, and is especially good when growing your mushrooms outdoors.

Blue Oyster mushrooms are very aggressive so it is possible to spawn to bulk in open air without worrying too much about sterile procedure. This is why Blue Oyster Mushrooms are great for beginners.

Pinning Conditions for Blue Oyster Mushrooms

Decrease the temperature for the pinning conditions to around 60 F or 15 C with humidity kept constantly high at 95-100%. The most important pinning trigger is normally fresh air exchange so open up your substrate to the outside atmosphere.

A good amount of fresh air exchange is vital to trigger the formation of pins, and you can help to increase humidity by spraying the substrate with water.

Drying out may be an issue at the start of the pinning phase, but with consistently high humidity levels, this problem can easily be overcome.

Fruiting Conditions for Blue Oyster Mushrooms

During fruiting maintain temperatures between 59-68 F or 15-20 C, with humidity reduced to 85%, and a CO2 level below 800 ppm. Fruits should start to appear within at least 5 days after the pinning stage.

Too much humidity and the formation of droplets upon the fruits may lead to bruising, marks, or deformities.  The average indoor home environment is too high in CO2 to grow ideal Blue Oyster Mushroom, so this species is recommended for outdoor grows.

If your Blue Oyster Mushrooms is growing noticeably leggy, it is a sign that not enough fresh air is being circulated.
Mushrooms emit their own CO2, and the reason they might be growing longer is that they are trying to reach more oxygen. Therefore, increase the supply of fresh air by putting the Blue Oyster Mushrooms outside on a window frame or at least near a source of fresh air.

The Best Substrate for growing Blue Oyster Mushrooms

Blue Oyster Mushrooms can be grown on several surfaces, including sterilized hardwood substrate or any material rich in cellulose, e.g. hay, sugar cane mulch, cardboard. The gold standard for growing Blue Oyster Mushrooms is master mix, this is simple a 50/50 mix of soy bean hulls and hardwood sawdust hydrated, sterilized then  inoculated with spawn.

Blocks of sawdust or straw bales that have been pasteurized are also good options, especially if you are hoping for multiple harvests.

Any decaying organic matter is a possible choice for cultivation, including paper towels, grass, and other industrial waste, thanks to Blue Oyster's ability to break up and decompose the material.

When to harvest Blue Oyster Mushrooms?

Blue Oyster Mushrooms are at their best, taste-wise, when still young, so avoid letting your mushrooms grow too old. When the caps start to flatten or turn upwards, this is the time to harvest. You want to do this before they begin dropping spores (which will appear as white “dust”).

Twist off by hand or cut entire clusters with a sharp knife, and try not to damage the remaining body if you are planning to re-fruit and hopefully grow several more crops.

Two days after your first harvest, submerge the substrate in water overnight, then re-commence fruiting your mushrooms. Spray with water twice a day, and within 2 weeks, a second harvest will appear. This can be repeated once more before the substrate is exhausted of the necessary nutrients.

To store for longer, try and keep your Blue Oyster Mushrooms in a cluster. They will keep relatively long in a fridge, and you can also use a dehydrator to preserve long-term.

Fruiting Containers for Blue Oyster Mushrooms

Thanks to the versatility of Blue Oyster Mushrooms, they can be grown in a wide range of containers. Buckets, Jars, net baskets, Mycobags can all be used to fruit Blue Oyster Mushrooms, as long as you can provide the correct humidity and fresh air exchange Blue Oyster Mushrooms should thrive.

Buckets with holes drilled in to allow the fruit to form and grow can be an attractive feature for your garden, and would especially work well with outdoor growing conditions – just remember to keep the top covered so the fruits can only emerge from the drilled holes.

Poly tubing, combined with layers of straw, is another possibility. However, make sure the straw is not too densely packed; otherwise, air will not be able to reach the growing fungi, and contamination may occur.
Grow bags are perhaps the easiest fruiting container, with slits cut in the side to allow the fruits to grow through.

Yield of Blue Oyster Mushrooms

Blue Oyster Mushrooms can offer an extremely high yield, with up to 200% production. Those mushrooms cultivated in high CO2 conditions will have long, thick stems and small caps; as the cap is the tastiest part of the Blue Oyster, it is, therefore, best to have as low a CO2 level as possible throughout the growing period and keep as much fresh air circulating as you can. You will most likely get a better yield with an outdoor grow.

What do Blue Oyster Mushrooms taste like?

A good substitute for meat, Blue Oyster Mushrooms can be served in soups, sautéed, fried in butter with garlic and herbs, or simply served on their own. Their thick and meaty flesh gives them a rich and distinctive taste, with a slight kick of anise. 

They are ideal for grilling as mushroom steaks, and some Central European cuisines use them in stews in place of meat.

Blue Oyster Mushrooms are best eaten young, as their flesh toughens with age, and can become sour in taste. The stems can also be tough and chewy, and you may be best just sticking to the cap for your meal.

There are many recognised medicinal benefits of eating Blue Oyster Mushrooms. They boast a high protein content, as well as numerous B vitamins, essential amino acids, antioxidants, and vitamins and minerals. Studies have shown they can play a role in reducing both tumor sizes and inflammation throughout the body, as well as treating high cholesterol. 

The development of plaque in major arteries can also be reduced by introducing Blue Oyster Mushrooms to your diet.

Are Blue Oyster Mushrooms Low Fodmap?

Yes! Blue Oyster Mushrooms are considered a low fodmap food source.

Are Blue Oyster Mushrooms Hallucinogenic or  Psychedelic?

No, Blue Oyster Mushrooms do not contain any psychedelic substances.