Rachel BairdPearl Oyster mushrooms (Pleurotus ostreatus) are a delicate and delicious fungi that grow year-round, even in the winter. These pearls of the forest grow on both living and dead deciduous trees, and encompass many species in a range of colors, including white, grey, yellow, blue, and pink.
Oyster mushrooms grow wild in many temperate forests around the world. Many people forage for them, and you can also find them in grocery stores and farmer’s markets. They are also among the easiest and most cost-effective to grow at home.
Learn more about the different varieties of oyster mushrooms, and the benefits of foraging and growing these pearls of the forest.
What Are Oyster Mushrooms?
Pearl Oyster mushrooms (Pleurotus ostreatus), its Italian name meaning “side-ear” which refers to its shape, is a widespread and popular gourmet mushroom in temperate and subtropical forests around the world. Acting as a primary decomposer, oyster mushrooms are beneficial to the forests, breaking down vital nutrients for plants and organisms to use. They are also capable of digesting and killing nematodes in the soil, making them helpful in the garden as well.
They grow in some regions in the wild year-round, and are happy on a wide range of substrates, including deciduous trees, cardboard, and straw.
Key Identification Features:
- A fan-like or oyster-shaped cap
- Varies in color from white to gray, and tan to dark-brown
- The gills of the mushroom continue along the stem and are white or cream-colored
- Forms in shelf-like clusters
- The stubby stem (if present) is off-center, coming out of the side of the mushroom
Other related species include:
- Pink oyster (Pleurotus djamor)
- Blue oyster (Pleurotus ostreatus (var. columbinus)
- Golden oyster (Pleurotus citrinopileatus)
- King oyster (Pleurotus eryngii)
- Phoenix oyster (Pleurotus pulmonarius)
Note: While the Elm Oyster (Hypsizygus ulmarius) shares its name, it is not a true oyster.
Oyster Mushroom Fungi Facts
Oyster mushrooms are fast growers, capable of producing mushrooms weeks after inoculation (depending on the strain and method), in comparison with months to years with other species. Their caps reach a size of anywhere from 1 to 12 inches.
This gourmet mushroom is popular for indoor cultivation, outdoor cultivation, and foraging.
- Oyster mushrooms grow on a wide range of substrates, including straw
- Oyster mushrooms are highly efficient in converting substrate mass into mushrooms, meaning they are among the highest-yielding mushrooms
- Oyster mushrooms are high in protein, vitamin B, and non-starchy carbohydrates
Oyster Mushroom Senses
Oyster mushrooms have a delicate, velvety, and meaty texture, and when pan-fried, the edges are crisp. Additionally, they have a mild and nutty flavor when cooked and are an elegant feature in many savory dishes. The caps of these mushrooms are soft and smooth and are sometimes described as smelling slightly like seafood, licorice, or anise. The large gills often continue down the stem.
Where to Source Oyster Mushrooms
In the Store
Commercial cultivation started in Germany during WWI, and today many people grow oyster mushrooms around the world. They are the third-largest cultivated mushroom in the world (after shiitake and Agaricus bisporus).
You can find oyster mushrooms in many grocery stores and farmer’s markets around the world — especially in Asian countries and Asian grocery stores — in fresh, frozen, canned, and dried varieties. While the United States produces the majority of the world’s button mushrooms, China is the world supplier of oyster mushrooms, producing over 85% of those commercially sold.
Growing Outdoors
Growing in Garden Beds
Oyster mushrooms are easy to grow outdoors, and by far, the most popular substrate for growing is on straw. Not only is straw cheaper to source than hardwood logs or wood chips, oyster mushrooms also tend to colonize and produce quite quickly on straw. Wheat and oat straw are among the most common, and it’s best practice to pasteurize the straw prior to use to kill off bacteria, other fungi, and weeds.
To pasteurize the straw, submerge it in hot water (71°C or 160°F) for about 1 hour. This step is optional for outdoor growing, but it is a good idea to reduce grass growing in your beds.
Select a garden bed for your oyster mushrooms. It can be a dedicated mushroom bed or spread the spawn between rows in your vegetable garden.
- Use the lasagna method to layer the spawn in between 1 to 2-inch moist layers of substrate.
- If you didn’t pasteurize the straw, either soak the substrate ahead of time or spray down each layer thoroughly as you are laying it.
Growing on Logs
Oyster mushrooms are also popular to grow on logs, and fruit on aspens, cottonwood, sweetgum, and most other hardwoods. Since there are many varieties of oyster mushrooms, some may be more prolific on different trees, so always research the exact strain prior to inoculating.
Logs usually fruit within 6 to 12 months of inoculation and can continue producing for upwards of 3 years (depending on the type and diameter of the tree used). One log can produce up to 1 pound of mushrooms yearly.
- Using a recently harvested log — about 3 to 4 feet in length and 4 to 6 inches in diameter — drill 1-inch holes into the logs using a power drill and drill bit.
- With a hammer or mallet, tap the plug spawn into the holes.
- Then, using a dauber, cover the plug spawn with melted wax.
Store logs in a shaded location and water weekly during periods with no precipitation. Once fully colonized, shock the logs by submerging them underwater in a large stock tank for 24 hours.
A huge benefit to growing oyster mushrooms outdoors, rather than indoors is that allergy sufferers shouldn’t be as allergic when they release spores. Oyster mushrooms release massive amounts of spores when fully mature, and in indoor settings, this can cause respiratory issues for some people.
Growing Indoors
Indoor growing is also common, especially for large-scale commercial operations, as the inoculation to fruiting time is reduced in this controlled environment. Since you also don’t have to compete with the weather, like with outdoor growing, you can produce mushrooms year-round.
Oyster mushrooms grow best indoors in polypropylene bags or as blocks on wire racks. Growing in bags is often preferred as it is easier to manage and control contamination. Sawdust spawn (often mixed with a small amount of rice or wheat bran) is an example of a growing medium, but since oyster mushrooms grow on many substrates, many cultivators experiment with different grains. You can purchase pre-inoculated sawdust spawn or liquid cultures in syringes to create your own.
Indoor mushroom growing requires a high level of sanitation. Therefore, always follow the directions from where you purchased your spawn or cultures, for best results. For those new to growing mushrooms at home, try a mist and grow mushroom kit at home first, for a fun and easy introduction to growing mushrooms.
Varieties of Oyster Mushrooms
Depending on your climate and current season, you may want to experiment with different varieties of oyster mushrooms to see what grows best. Blue, pearl, and king oyster mushrooms, for example, prefer cooler temperatures and are best grown in the spring and fall months. Pink, golden, and phoenix oyster mushrooms, on the other hand, prefer the warm and humid temperatures of summer.
| Variety | Preferred Fruiting Temperature | Preferred Relative Humidity for Fruiting | Best Time of Year for Outdoor Growing | Expected Yield |
| Pearl Oyster | 10 to 21°C (60 to 70°F) | 85 to 90% | Spring and Fall | High Yield |
| Blue Oyster | 12 to 24°C (55 to 75°F) | 85 to 90% | Spring and Fall | High Yield |
| King Oyster | 15 to 21°C (60 to 70°F) | 85 to 90% | Spring and Fall | Medium Yield |
| Pink Oyster | 20 to 30°C (70 to 85°F) | 85 to 90% | Summer | Medium to High Yield |
| Golden Oyster | 21 to 29°C (70 to 85°F) | 90 to 95% | Summer | Low Yield |
| Phoenix Oyster | 18 to 24°C (65 to 75°F) | 85 to 90% | Summer | High Yield |
Most Common Uses for Oyster Mushrooms
Oyster mushrooms are a versatile gourmet mushroom used in a number of culinary dishes. They are best fried, braised, boiled, or sauteed, and are excellent in risottos, soups, and pasta recipes. In addition, these mushrooms are also popular mixed with BBQ sauce as “Pulled Pork,” and fried up in a breading as “Vegetarian Calamari.”
Oyster mushrooms do have a short shelf life (about 2 to 3 days refrigerated), so are best eaten when fresh. Therefore, if you can’t use them all in time, you can also dry, freeze, or pickle them for longer storage.
The Pearls of the Forest
Oyster mushrooms really are the pearls of the forests, growing on a wide variety of deciduous trees, and stunning with a range of colors from yellow to blue and pink. Growing in the wild around the world, they are popular among foragers, as well as indoor and outdoor cultivators. They are arguably the easiest and most cost-effective gourmet mushrooms to grow at home and in the garden.
So, what are you waiting for? Start growing oyster mushrooms today!
Sources:
- Stamets, Paul. Growing Gourmet and Medicinal Mushrooms, 3rd edition, 2000.
- Grow Mushrooms Canada: Growing With Plug Spawn
- https://mdc.mo.gov/discover-nature/field-guide/oyster-mushroom
- https://www.inaturalist.org/taxa/48494-Pleurotus-ostreatus
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5608979/
