Oyster mushrooms (Pleurotus species) are where almost everyone should start. They colonise grain in a week, run through a coir tub in another, fruit heavily, and tolerate the humidity and temperature swings of an ordinary house. They also come in enough varieties that there is one for every Australian climate, from a Darwin verandah in summer to a Hobart spare room in winter.

Pick your oyster

Substrate and spawn

Pink, blue, pearl and phoenix oysters fruit well on our coir-based CVA and CVWA blends and even better, if firmer fruit matters to you, on hardwood. King oyster is a hardwood-only mushroom. Spawn coir tubs at 1:2 to 1:4 by weight and hardwood blocks at 1:4 to 1:5. The grow builder picks bag sizes for any tub.

Step by step

1. Grain

   Inject 2 to 5 ml of liquid culture into a sterilised grain bag. Oysters have a 1kg bag white in 7 to 14 days. Or buy colonised spawn.

2. Spawn

   In a still air box, mix the spawn through a substrate bag and pack a tub 6 to 10cm deep, or keep it in the bag as a block.

3. Colonise

   20 to 26°C in the dark. Coir tubs are white in 5 to 10 days at 1:2. Give it three more days to consolidate.

4. Fruit

   Open the tub or cut the bag. Humidity 85 to 95%, indirect light, and fresh air several times a day. Pins in 3 to 5 days.

5. Harvest

   Twist whole clusters off at the base when the cap edges flatten and before they curl upward. The flush ripens over about two days; check it twice a day.

The fresh-air rule

Oysters produce more CO2 than almost any other cultivated mushroom and respond to it badly: long, pale stems with tiny caps, or caps that never open. If your oysters look like that, the fix is always more air. Crack the lid wider, fan the tub a few times a day, drill more holes and stuff them with polyfill, or move the block somewhere with gentle airflow. Humidity drops as air moves, so mist more as you ventilate more.

Australian notes

• Summer in Queensland and the Top End: pink and phoenix oysters, almost effortless.
• Summer in the south: pearl or phoenix; keep blue for the cool months.
• Winter anywhere south of Brisbane: blue oyster, and the cold will tint the caps deep blue.
• Fast and perishable: pink oysters keep two or three days in the fridge. Grow what you will eat that week.

Second flush

After harvest, remove stubs, rest the tub for five to seven days in fruiting conditions, and if it feels light, soak the block or mist heavily and let it drain. The second flush follows in a week or two and is usually about half the first. A third is common on coir tubs that have been kept clean.

Written by the Aus Myco Kingdom crew. Everything here is general growing information for gourmet and medicinal species; your room, your climate and your culture will have the final say.