Oyster var. summer

Pleurotus ostreatus

Available as

Mother cultures (Petri dish)
Grain spawn
Sawdust spawn

About this strain

Fruiting bodies are medium to large in size, greyish brown in colour and light grey when warm. The mycelium colonises the substrate quickly, and the fleshy mushrooms store and ship well.

Variety for year-round cultivation when good ventilation and evaporation are provided. Above 19°C, fruiting bodies may be of slightly lower quality; high humidity and poor evaporation can reduce resistance to bacterial blotch.

How to grow it

Preparation

Substrate: wheat or rye straw chopped to 2–5 cm, pasteurised; flax or hemp shives and supplemented hardwood sawdust also work well; moisture approx. 70–75%
Spawn rate: approx. 2% of wet substrate weight

Growing stages

Spawn run (incubation)
Temperature
air 20–22°C, substrate approx. 25°C (22–26°C)
Duration
17–22 days
Monitor the core temperature of the blocks — above 28°C the yield drops by 25–30%.
Primordia formation
Temperature
approx. 16°C (14–18°C)
Humidity
90–95%
Duration
5–7 days
CO₂
<1,000 ppm
Fresh air
increased
Light
8–10 h / 24 h
Cut holes in or remove the film and lower the air temperature to approx. 16°C — no cold shock is needed.
Fruiting
Temperature
13–18°C (max. 22°C)
Humidity
1st flush 72–75%, 2nd flush 80–85%
CO₂
<1,000 ppm
Fresh air
stable, gentle
Light
8–10 h / 24 h
Recirculation: gentle. Optimum approx. 16°C; below 13°C the yield drops markedly. Sensitive to excess CO₂ — do not overload the room.

Harvest

Flushes: 2–3 (usually 2 distinct ones)
Between flushes: approx. 10–14 days

The cap edges are brittle — pick carefully, before they flatten. After harvesting remove stem remnants and reduce misting for a few days while ventilating well. Yield: approx. 18–25% of fresh substrate weight, of which the first flush gives approx. 55–60%.

Please note: these growing parameters bring together the experience of practising growers — a starting point, not a guarantee of results. Every grow has its own substrate, climate and equipment, and even small differences can noticeably change the yield. Adjust these values to your own conditions.