Logs with plug spawn

What it is

Fresh-cut hardwood logs are drilled, the holes are filled with spawn and sealed with wax, and the logs sit in a shady "laying yard" for about a year before shiitake begin to fruit. A log then fruits twice a year for three to four years¹.

The UVM and Cornell guide recommends logs 4 to 6 inches across, because that size has the most sapwood for its volume; bigger logs may need 18 to 24 months¹. Cornell suggests inoculating within a month of cutting². Wax over each hole seals in moisture and reduces contamination by other fungi¹.

Shiitake logs can be "forced": soaked in cold water for 12 to 24 hours, they fruit within about 7 to 14 days¹. That predictability is why Cornell’s researchers settled on shiitake as the most practical log species².

What it suits

Shiitake above all, plus oyster and lion’s mane on logs².

Species notes are on the species page; for the mushrooms themselves, see Ohio Gourmet Mushrooms.

Equipment

• Fresh-cut hardwood logs 4–6 inches across¹
• Plug or sawdust spawn
• A drill with the matching bit (or an angle-grinder adapter)
• Food-grade wax, a pot to melt it and daubers¹
• A shady spot, 75–100% shade year-round¹
• A tub or tank for soaking, if you plan to force fruit

Time to first harvest

6–18 months for shiitake; 4–12 months for oyster. Cornell gives incubation of 6 to 18 months for shiitake logs and 4 to 12 months for oyster logs². The UVM guide puts shiitake at about a year in the laying yard before fruiting starts¹.

Contamination and other risks

• Native fungi colonising the log before your spawn does, which is why the guides say to inoculate soon after cutting²¹.
• Logs drying out. Cornell soaks logs for 6 to 8 hours when the ends crack wide enough to fit a dime².
• Bark damage, which should be waxed over during inoculation¹.

Steps, in overview

1. Cut. Cut healthy hardwood, ideally in the dormant season when bark is tight¹.
2. Drill. Drill rows of holes around the log; the UVM guide sizes the number of rows to the log’s diameter¹.
3. Fill. Tap in plugs or pack sawdust spawn.
4. Wax. Seal each hole with hot wax¹.
5. Stack in shade. Stack in deep shade and keep logs from drying out¹².
6. Force or wait. Once colonised, soak shiitake logs 12–24 hours to trigger a flush¹, or let rain do it.

Common mistakes

• Letting logs sit for weeks before inoculating "so the tree can die"; Cornell calls this a misconception².
• Using huge logs you cannot lift into a soaking tank.
• Leaving logs in full sun¹.