Staff Pick 3782 — ShiitakeGrain Spawn 5 lb

Shiitake 3782 Mushroom Spawn – 5 lb Bag

Shiitake 3782 (Lentinula edodes) is a cold-weather strain engineered for reliable fruiting at lower temperatures. This is the strain you want when growing Shiitake through fall and winter in Canadian conditions, whether in unheated or lightly heated grow spaces. Paired with a warm-weather strain like 3790, you can maintain year-round Shiitake production without gaps in your harvest schedule.

Why Growers Choose Shiitake 3782

• Cold-weather fruiting – Produces quality mushrooms at 10–16°C, ideal for Canadian fall and winter production.
• Year-round production – Complements warm-weather Shiitake strains to keep your supply chain uninterrupted across all seasons.
• Premium quality fruit bodies – Cold fruiting temperatures produce thicker, denser caps with superior texture and longer shelf life.
• Established commercial strain – Strain 3782 is trusted by professional Shiitake farms across North America for consistent performance.

What You Get

Each 5 lb bag contains fully colonized organic millet grain spawn produced at our CFIA-licensed facility in Brantford, Ontario. Lab-tested genetics and sterile in-house production ensure every bag meets the quality standard commercial growers require. Our grain spawn is ready to use upon arrival.

How to Use

Mix grain spawn at a 10–15% rate into supplemented hardwood sawdust substrate. Pack into grow bags and colonize at 21–24°C for 8–12 weeks. Shiitake blocks are ready to fruit when the surface has turned fully brown and the block feels firm. Trigger fruiting with a 12–24 hour cold-water soak, then move blocks to your fruiting room. Strain 3782 thrives in cooler fruiting environments where it produces thick, high-quality caps.

Growing Conditions

• Fruiting temperature: 10–16°C (50–61°F)
• Humidity: 80–90% RH during fruiting
• Light: Indirect ambient or 12-hour cycle
• Fresh air: Moderate air exchange
• Substrates: Hardwood sawdust with wheat bran supplementation

Complete your year-round Shiitake lineup with our Shiitake 3790 Mushroom Spawn for summer production. Need agar for culture work? Check out our pre-made agar plates.