Songxiang No 1 Shiitake Variety Characteristics and Cultivation Guide
A practical operating reference for substrate preparation, spawn running, browning, primordia induction, fruiting and inter-flush recovery.
Songxiang No. 1 is a fast, broadly temperature-tolerant shiitake variety intended for winter and spring production on tiered racks. Its commercial strengths are early fruiting, strong yield potential, uniform colonisation and substantial, well-shaped fruiting bodies.
Variety characteristics
The mycelium is white, vigorous and dense, with an even, woolly growth pattern and orderly substrate penetration. The stated growth range is 10-29°C, with an optimum of 22-24°C, relative humidity of 60-65% and a preferred pH of 5.0-6.5. Under suitable conditions, bags may become fully colonised in about 35-40 days.
Primordia are described as strong and appropriately distributed rather than excessively crowded. Fruiting bodies are generally solitary and rounded, with dense flesh and a thick, light grey-brown cap carrying visible scales. The source dimensions are 51-66 mm cap diameter, 11-14 mm cap thickness, a white gill surface and a firm, tapered stipe approximately 44 mm long and 14 mm in diameter.
Substrate, nutrition and bag preparation
Use healthy, contamination-free spawn of the correct physiological age. Hardwood sawdust from oak and other dense broadleaf species is preferred because its lignin content supports nutrient accumulation. As a general rule, the substrate carbon-to-nitrogen ratio should remain in the range of 20:1 to 30:1. The source notes wheat-bran inclusion of about 15% for early, warm-tolerant strains and up to 20% for later, cool-tolerant strains.
| Component | Share | Operating note |
|---|---|---|
| Hardwood sawdust | 79% | Use clean, dense hardwood material with no dry clumps. |
| Wheat bran | 20% | Distribute evenly throughout the mix. |
| Gypsum | 1% | Blend fully before moisture adjustment. |
| Water | 52-55% moisture | The document also cites about 60% as a general upper reference; the strain-specific formula is 52-55%. |
Fill 16 × 58 cm low-density polyethylene bags with approximately 1.3 kg of dry substrate per bag. Pack the substrate firmly and evenly. Excess internal voids increase respiratory losses, while excessive water can restrict oxygen; insufficient water produces thin, weak mycelium.
Inoculation and spawn running
Sanitise the inoculation environment and sterilise tools such as forceps and inoculation spoons. The source specifies 30 minutes of ultraviolet treatment for an inoculation box or room. Any chemical fumigation method must be replaced or implemented only as a validated, legally permitted procedure by trained personnel. Operators should wear clean protective clothing, caps and masks.
- Open the cooled bag under controlled clean conditions.
- Introduce spawn evenly at a rate of approximately 5-10%.
- Seal the bag immediately to limit airborne contamination.
- Keep movements efficient so spawn is not exposed longer than necessary.
Maintain darkness or low light, 22-26°C and 60-70% relative humidity with reliable air exchange. Ventilate once or twice daily for about 30 minutes, without directing cold air onto the bags. A cross-stack pattern supports airflow. Initial stack temperature should be 23-25°C to establish the inoculation points, then 20-22°C through the middle phase. When the logs approach maturity, 23-25°C may be used again. Keep day-night fluctuation within 2-3°C and monitor the stack during every turning operation.
Fruiting management by stage
1. Browning
Increase diffuse light, hold 20-24°C and about 80% relative humidity, and strengthen ventilation. White aerial mycelium should gradually pigment into an even brown protective skin. Excessive browning produces a thick skin that can suppress fruiting; insufficient browning leaves the log vulnerable to rapid water loss.
2. Primordia induction
Maintain 20-22°C during the day and 10-12°C at night, creating an 8-10°C difference for 3-5 days. Raise room humidity to 85-90% by misting the air rather than spraying bags directly. Ventilate two or three times daily for about 30 minutes. Rice-grain-sized white primordia should appear after approximately 7-10 days.
3. Young fruiting bodies
Hold 15-18°C and 85-90% relative humidity. Ventilate two or three times daily for 20-30 minutes and keep carbon dioxide below 0.05%. Remove malformed, diseased or excessively dense primordia so selected mushrooms receive sufficient nutrition.
4. Market-size mushrooms
Maintain 12-20°C and reduce humidity to 80-85%. Avoid standing water on caps. Ventilate three or four times daily for about 30 minutes. Light may be increased to 1,000-1,500 lux for 4-5 hours per day to support normal deep-brown cap colour and market quality.
Inter-flush recovery and water replenishment
After the first flush, remove stipe bases, damaged mushrooms and debris. Recondition the mycelium before initiating the next flush. Water may be restored by injection or soaking. For soaking, puncture the logs, stack five to eight layers under a weighted board and submerge the upper bags by 7-8 cm. Use cool water; if water exceeds 20°C, replace it promptly with colder water.
Before the first flush, use bag weight loss to decide whether rehydration is necessary. If weight loss does not exceed approximately 30%, the source advises that additional water may not be required. With every method, record water uptake and crop response rather than applying one fixed volume to all logs.