Inoculate hardwood logs for outdoor production

Drilling holes in freshly-cut hardwood logs and filling them with plug spawn produces oyster mushrooms outdoors for 3-6 years per log. Low maintenance after setup — the logs fruit naturally in spring and fall rains.

Steps

1. Source fresh logs: Cut 3-6 inch diameter hardwood branches or logs (oak, maple, beech, poplar) into 3-4 foot lengths. Use wood cut within the last 2-4 weeks — too old and competing fungi colonize first.
2. Drill inoculation holes: Use a 5/16-inch or 12mm drill bit to drill holes 6 inches apart in a diamond pattern, 1-1.5 inches deep.
3. Insert plug spawn: Tap pre-inoculated wooden dowel plugs into each hole with a hammer. 30-50 plugs per 3-foot log. Plug spawn costs ~$20-25 per 100 plugs from suppliers like Field & Forest Products or North Spore.
4. Seal with wax: Melt cheese wax or soy wax and dab over each plug to prevent drying out. Also seal the cut ends.
5. Stack in shade: Lean logs against a fence or stack in a crib pattern in a shady, moist area. Water during dry spells.
6. Wait 6-12 months: Colonization takes time. First fruits appear the following spring or fall.

Tips

• Each log produces 1-2 lbs of mushrooms per year for 3-6 years
• Soaking fully-colonized logs in cold water for 24 hours triggers an early flush ("force fruiting")
• Avoid softwoods (pine, cedar, fir) — their resins inhibit mushroom mycelium