Summer Ground-Based Cultivation of Shiitake Mushrooms in Cold Sheds

This off-season cultivation method strips plastic bags from mature shiitake spawn logs and buries the logs partially in soil. Covered logs resist miscellaneous fungi contamination, absorb water and nutrients naturally, and skip repeated rehydration work. It solves the shortage of fresh shiitakes in northern China during hot summers and is suitable for large-scale promotion. Core technical procedures are summarized below:

1. Construction of Cooling Fruiting Sheds

• Site requirements: clean environment, good water source, large temperature difference between day and night; altitude ≥600 meters preferred.
• Cultivation cycle: early May to November. Double-layer shading structure is adopted to reach 80% shading rate for effective cooling.
• Standard shed size: 35m × 6.4m, ridge height 2.5m. Drainage ditches and surrounding plastic skirts are required. Micro-sprinklers are installed inside to humidify and cool.
• Layout: 12 sheds per cultivation block with reserved access roads. About 1 mu (667 m²) fruiting area for 8,000 spawn bags.

2. Preparation of Cultivation Beds and Casing Soil

• Build north-south beds with specified widths and 6–8 cm depth; set aisles with sprinkler pipes.
• Disinfect the field by sun exposure and lime application before use.
• Use sandy loam (sand content ~40%) as casing soil; avoid pure sand or clay. Lay 2 cm dried sandy soil on bed bottoms to prevent rotting and contamination.

3. Spawn Bag Hardening in Sheds

• Do not remove bags immediately after transporting into sheds. Stack bags for 7–10 days of adaptive hardening under day-night temperature differences.
• Adjust stacking ways timely to prevent overheating. Only deploy logs with mature, discolored mycelium and primordia for casing.
• Immature spawn logs are loose, easily contaminated, low-yield and not recommended for bed placement. Rough transportation easily causes excessive weak embryo mushrooms.

4. Bag Stripping, Log Placement & Waste Plastic Treatment

• Operate on sunny mornings at 15–25°C; avoid rainy, windy or high-temperature weather. Cut and peel bags gently.
• Saturate beds with water in advance. Place logs horizontally, inoculation points upward with 1.5 cm gaps. Fill gaps with soil to 3/4 log height and keep the top exposed for fruiting. Water thoroughly after arrangement. One standard shed holds roughly 3,000 spawn bags.
• Collect waste plastic bags uniformly for recycling. Growers can recover around one third of new bag costs while avoiding pollution.