Blue oyster mushrooms (Pleurotus ostreatus) may be the most well-known gourmet edible mushroom and were one of the first mushrooms grown and sold at North Spore back in 2014. They are one of the easiest to cultivate and are highly nutritious, making them a popular choice for home cultivators and commercial growers alike. In this species spotlight we cover the basics of blue oyster cultivation so let’s dive in and explore the many ways this popular mushroom can work for you!
Blue oyster mushrooms grow in large, shelf-like structures made up of dense, overlapping clusters of individual fungi that vary in color from steely blue in cultivated varieties to brown and white in wild specimens. Their scientific name, deriving from the Greek “pleura” meaning ‘side’ and “ot” meaning ‘ear’ suggesting it appears like a “side ear” growing from a tree, with “ostreatus” being Latin for “like an oyster shell.” Fruiting bodies can vary in shape and size depending on growing conditions like humidity, CO2 and sunlight.
That being said, they are often fan or oyster-shaped with smooth, flat or slightly indented caps that are typically 2-10 inches across with wavy edges. Gills are slender, white and decurrent, meaning they are attached to the stem and run most of the way down it. Stem length is dependent on substrate, as those growing from the top of a log or from a garden bed have more well-developed stems up to 3 inches tall, compared to those growing from the side of a tree or substrate block, which can lack stems altogether.
Blue oyster mushrooms growing in the typical style: dense, overlapping clusters of individual fungi
Blue oyster in its natural habitat
Blue oyster mushrooms are native to temperate and subtropical regions of the northern hemisphere, and can be found in North America, Europe and Asia. They are primarily saprotrophic, feeding on dead and decaying beech, oak, maple, chestnut, and birch logs, stumps and trees, helping to return vital nutrients and minerals to the soil. They are also considered omnivorous because they are known to consume nematodes for their nitrogen.
One study found that blue oysters in protein-poor environments produced a poison that paralyzes and kills nematodes prior to their ingestion from the inside out. Pearl oyster and Pleurotus ostreatus variety columbinus are both synonyms for blue oyster, which was first grown commercially in Germany in the early 1900s but is now available worldwide and known as hiratake in Japan.
Preferred Growing Methods & Substrates
@petrpal growing blue oysters in vertical bags
@frederickfamilyacre growing in buckets
@leboeufhomestead growing blue oyster from hackberry logs
Difficulty for Outdoor Cultivation: Beginner
Blue oysters are versatile and can be grown in a number of ways indoors and out. For indoor cultivation we recommend growing blue oysters from an Organic Blue Oyster ‘Spray & Grow’ Mushroom Growing Kit or from an Organic Blue Oyster Mushroom Grow Kit Fruiting Block in a fruiting chamber such as our ‘BoomRoom’ Automated Mushroom Martha Tent Grow Kit or in a monotub using a substrate mixture containing sterile manure and hardwood sawdust. We offer a complete monotub walk-through video here. Keep in mind that this species is sensitive to high CO2 levels and will require a fresh air exchange system if grown indoors. Outdoors, blue oysters can be grown on logs, totems, and stumps inoculated with plug spawn or sawdust spawn using a variety of tree species including maple, oak and cherry.
Blue oyster mushrooms can also be grown in more traditional garden beds or containers inoculated with grain or sawdust spawn. As outlined in our substrate compatibility guide, garden beds can be supplemented with various agricultural byproducts such as coffee grounds, grass clippings, leaf waste, straw, corn cobs, sawdust, banana leaves, cotton seed hulls, newspaper, and cardboard. When grown in beds or from containers blue oysters prefer straw over denser woody substrates such as wood chips but straw is preferable to hay as hay contains seed heads which are more prone to contamination. Straw bales or bagged chopped straw can be found at local garden centers, agricultural supply stores, or nearby farms. For a complete guide to growing mushrooms from buckets and containers please read our blog or watch our recent video!
Fruiting & Harvesting
Since blue oysters grow naturally in the colder climates of the northern hemisphere, they are adapted to growing and fruiting at colder temperatures, typically between 55 and 75 degrees F but can fruit as high as 95. They are fast growers and can colonize a grain bag or sawdust block in as little as a week. For outdoor beds and buckets, however, this process can take anywhere from 6 months to a year. Following colonization, they require humidity levels above 85 percent for fruiting, and can produce 2 to 3 flushes or crops per fruiting cycle depending on growing conditions.
Harvest young blue oyster clusters when the edges of caps are still slightly turned under. In this younger stage, less spores will be produced and shelf life will be extended. The mushrooms will keep up to three days when stored loosely in a brown paper bag in the refrigerator, and it is suggested that they be harvested in clumps for better storage to prevent dehydration. They can be frozen for up to three months or dried and kept in a sealed container away from direct sunlight for several months. For more mushroom preservation techniques, stay tuned to our blog for an upcoming article on the subject!
Blue oyster cultivated in the totem style ready for harvest
Nutrition & Medicinal Qualities
Generally, mushrooms are a rich, low-calorie source of vitamins B and D, fiber, protein, and antioxidants, beta-glucans and anti-inflammatory compounds and can serve as an ethical and sustainable meat replacement. Blue oyster mushrooms in particular contain lovastatins that have been shown to lower cholesterol levels in animal studies. This makes them a potentially beneficial food for individuals with high cholesterol levels, but more research is necessary to confirm it.
Versatile in cultivation and cuisine, blue oyster mushrooms have a unique mild flavor and texture profile that is sweet and meaty with hints of licorice. Perfect for braising, sautéing, roasting, frying, grilling, and stir-frying, they are richer and more flavorful than store-bought mushrooms. They can be added to soups and broths to contribute umami flavors, added to pasta and pizza, omelets, breaded and fried, and used as a substitute for seafood. They go well with various herbs including parsley, thyme, and sage, potatoes, aromatics including garlic, green onion, shallots, ginger, and lemongrass, leeks, along with asparagus, bok choy, bell pepper, miso, heavy cream, fish, and meats such a beef, poultry, and turkey.
Not sure where to start? Check out our video on harvesting and cooking with blue oysters. As we like to say with all mushrooms, if it is your first time eating this species, it is best to start with a small amount as some folks experience gastrointestinal upset and we recommend cooking until their liquid has cooked off and they begin to brown. Blue oysters can be dried for an extended shelf life and do not require rehydration before use.
Growing blue oysters can be a fun and rewarding hobby that produces a delicious and highly nutritious protein-based food. Their ease in cultivation and minimal space requirements make them an excellent choice for both home growers and commercial producers and their versatility makes them a fun mushroom to experiment with in a variety of cultivation settings. Visit our website for more information and we look forward to seeing how your blue oysters grow!