Giant Oyster
Pleurotus giganteus
The giant oyster is a heat-tolerant, funnel-shaped mushroom that is grown in sawdust and cottonseed bags, covered with soil and fruited at about 27 °C.
Pleurotus giganteus is a large edible oyster-type mushroom. The first cultivar was domesticated from a wild strain in Fujian, China, in the 1980s, and nearly 250 strains are known from China, Malaysia, Sri Lanka, Indonesia, Vietnam, Laos and Thailand. In a 2024 trial of 15 strains, 1 kg bags of 39% sawdust, 39% cottonseed hulls, 20% bran and 2% calcium carbonate (53–55% moisture) were autoclaved at 121 °C for 4.5 hours and spawned at 3%. They were incubated at 22–23 °C, 70–80% humidity and CO2 below 2,000 ppm in the dark for about 60 days. The room was then warmed to 27 °C and the bags were covered with soil to form fruiting bodies.
Cultivation parameters
Climate
| Colonization temperature | 22–23 °C |
|---|---|
| Overall cultivation temperature | 25–35 °C |
| Fruiting temperature | 27 °C |
| Incubation humidity | 70–80% |
| Air / CO₂ notes | In a 2024 strain trial, bags were incubated at 22–23 °C, 70–80% humidity and CO2 below 2,000 ppm in the dark for about 60 days; the room was then warmed to 27 °C for primordia and fruiting and the bags were covered with soil. Most strains grew best at 24–28 °C. The FAO manual lists 25–35 °C for cultivation in Thailand. |
| Cold shock | Not required |
Timing & substrate
| Colonization | 60 days |
|---|---|
| Primary substrate | Sawdust and cottonseed hulls with bran |
| Substrate options | Mixed sawdust, Cottonseed hulls, Bran |
Spawn & substrate preparation
| Spawn types | Grain or sawdust spawn |
|---|---|
| Spawn rate | 3% of substrate weight |
| Spawn notes | 3% in a 2024 bag trial. |
| Substrate moisture | 53–55% |
Practical literature-range
| Difficulty | Intermediate — A heat-tolerant species grown in bags and then covered with soil; reported efficiency is low |
|---|
Taxonomy & ecology
| Scientific name | Pleurotus giganteus |
|---|---|
| Also known as | Giant funnel mushroom, Gigantopanus giganteus |
| Family | Pleurotaceae |
| Order | Agaricales |
| Genus | Pleurotus |
| Lifestyle | Saprotroph |
| Cultivation status | Commercially cultivated |
How to grow Giant Oyster, step by step
- Mix and bag. Blend sawdust, cottonseed hulls, bran and calcium carbonate to 53–55% moisture and fill 1 kg bags.
- Sterilise. Autoclave the bags at 121 °C for 4.5 hours and let them cool.
- Spawn and incubate. Add 3% spawn and incubate at 22–23 °C, 70–80% humidity, in the dark for about 60 days.
- Case and fruit. Open the colonised bags, cover them with soil and warm the room to about 27 °C.
- Harvest. Pick the funnel-shaped fruiting bodies as they mature.
Growing notes
Most strains grew best at 24–28 °C, and the FAO manual lists 25–35 °C for cultivation in Thailand, so this species suits warm climates. The best biological efficiency in the trial was only 15.61%, so do not expect oyster-like yields. Strains differ a lot in yield and in the size and shape of the fruiting body, which is why a good strain matters more here than with common oysters.
Questions about growing Giant Oyster
What temperature does the giant oyster need?
Most strains grew best at 24–28 °C in a 2024 trial. The FAO manual lists 25–35 °C for cultivation, and the trial fruited the bags at 27 °C.
How long does it take to colonize?
About 60 days at 22–23 °C in the 2024 bag trial.
Does it need a casing layer?
In the trial, the colonised bags were opened and covered with soil, and the mushrooms formed through the soil cover.
How much does the giant oyster yield?
The best strain reached a biological efficiency of 15.61%, which is low compared with common oysters.
What substrate does it grow on?
A mix of 39% sawdust, 39% cottonseed hulls, 20% bran and 2% calcium carbonate at 53–55% moisture was used in the trial.