Gardeners may choose from among several varieties of edible mushrooms for growing on hardwood logs. Growers must match the type of mushroom to the type of wood available and provide the best growing conditions. Fruiting could begin in only months and may repeat regularly for several years, until the fungus consumes the log. Not every location or climate favors mushroom growth, but if wild varieties prosper in your area, growing your own is possible.
Harvest hardwood trees for use as mushroom logs from after leaf fall to early spring. Small healthy trees with straight sections 3 inches to 6 inches in diameter will be easier to stack and shift than mature trees. Cut the trees into 40-inch long sections.
Keep the logs clean and don't damage the bark. Stack the logs on temporary racks in a shady and sheltered area. Set concrete blocks 6 feet apart in rows 3 feet apart and lay 6-foot posts across them. Lay 40-inch spawn logs atop the posts.
Run a lawn sprinkler over the logs for two or three hours and then cover the logs with a plastic tarp. Let the wood soak under the plastic sheet overnight.
Melt a block of cheese wax in a double boiler. Melting in the double boiler prevents overheating; overheated wax could explode in a flash fire. Carry the double boiler to the logs.
Uncover the logs and mark plug locations with the punch, 6 inches apart down the length of the logs, beginning 2 inches from one end. Bore 5/16-inch diameter holes 1 inch deep at the marks.
Drive mushroom spawn plug dowels into the holes and paint them sealed with wax. Be sure neither the holes nor the spawn plugs dry out.
Rotate the log and drill a second row of plug holes 2 1/2 inches from the first. If the first row has plugs at 2 inches and 8 inches on the log, the first plug in the second row should be at 5 inches; the next at 11, and so on. Inoculate the entire surface with evenly spaced plugs.
Lay inoculated logs in a row end to end on the ground. Lean a second row against them. Stack a third row end to end on the base of the leaners, and lean a fourth row against that. Continue until all logs are stacked.