Gadenin日本語Get the appUnderstand what is happening inside the log
From the day you seal the last hole, the job is no longer yours; it belongs to the mycelium. The fungus grows out of each plug into the surrounding sapwood, digesting the wood as it goes, and it must colonise a large enough share of the log before it has the reserves to make a mushroom. On a four-inch (10 cm) oak log that takes anywhere from six to eighteen months depending on wood species, log diameter, temperature and how well you kept the moisture up.
This period is called the spawn run, and the hardest part of it is that there is almost nothing to see. No mushrooms, no obvious change, just a stack of logs in the shade. Growers who have not been warned about the timescale conclude at month four that the logs have failed and break the stack up. Do not do that. The one visible clue arrives partway through: white or cream mycelium appearing on the cut ends of the log, spreading outward from the center in a pale fan.
Warmer sites run faster than cold ones. In a mild climate a thin alder or maple log may be ready to fruit in six to nine months, while a thick oak log in a cold region can take a year and a half. Species and diameter set the floor; nothing you do speeds the process beyond that.
| Stage | Rough timing after inoculation | What you can see |
|---|---|---|
| Establishment | First 1 to 2 months | Nothing; wax seals intact, bark unchanged |
| Early run | 2 to 6 months | Faint pale patches under the wax on some plugs |
| Mid run | 6 to 12 months | White mycelium visible on the cut ends |
| Full colonisation | 9 to 18 months | Cut ends mostly white; log sounds duller when tapped |
| First fruiting | 6 to 18 months | Small brown pins push through the bark after rain or a cold snap |
Where to stack the logs and how
Choose deep shade with good air movement, roughly seventy to eighty percent shade through the day. The north side of a building, under evergreens, or in the shade of a dense hedge all work. Direct summer sun is the enemy: an hour of afternoon sun on bare bark cooks the mycelium in the outer sapwood, which is precisely where it needs to be strongest.
Keep the logs off bare soil. Contact with the ground looks harmless but it puts your log in direct touch with every soil fungus in the yard, and those competitors are far better at colonising wet wood than shiitake is. Lay a couple of scrap rails, concrete blocks or pressure-treated bearers down and stack on those, with the lowest log at least four inches (10 cm) clear.
Two stacking styles cover most situations. A crib stack, with logs laid in alternating layers like a log cabin, holds moisture well and suits dry sites. A lean-to or A-frame stack, with logs leaning against a horizontal rail, dries faster and suits wet climates and the period once the logs are colonised. Start in a crib to hold moisture through the spawn run and switch to a lean-to when you begin forcing flushes.
Never stack shiitake logs against a wall in full sun with a plastic sheet over them. The sheet traps heat, the temperature under it climbs well past 100F (38C) on a clear day, and the mycelium in the outer inch of wood is killed outright.
Moisture is the one thing you actively manage
The mycelium needs the log to stay at roughly thirty-five to forty-five percent moisture content, which in practice means the log should feel heavy and sound dull when you knock it. A log that has dried out sounds hollow and rings, feels noticeably light, and shows deep radial cracks opening at the cut ends. Cracks a quarter inch (6 mm) wide are a warning; cracks you can slide a finger into mean the outer sapwood has already dried and part of the colony is dead.
In a normal rainy season, logs in deep shade need no watering at all. During a dry spell of two weeks or more, water the stack thoroughly, soaking the bark until run-off, once a week. In a hot dry climate, or where the logs sit under a roof overhang and never get rain, plan on a heavy watering every four or five days through summer.
Do not overdo it. Waterlogged wood goes anaerobic, sours, and invites bacteria and green mold. If the stack sits in a hollow that puddles after rain, move it. The target is consistently damp wood, not a log sitting in water.
- Check the cut ends monthly Look for white mycelium spreading from the center and for cracks opening. Both tell you more about the log's condition than the bark does.
- Lift one log and judge the weight Keep one log as a reference and lift it every few weeks. You learn what a well-hydrated log feels like far faster than you learn to read the bark.
- Water in the cool of the day Soak the stack early in the morning or in the evening so the water goes into the wood rather than evaporating off warm bark.
- Restack once a year Turn the logs over and swap top layers with bottom layers each year so all logs get similar moisture and light. Note in your records which logs you moved.
What not to do while you wait
Do not fertilize. A shiitake log needs no feeding of any kind, and anything nitrogen-rich splashed onto the bark feeds bacteria and competitor molds instead. Do not paint, oil or wrap the logs. Do not drill extra holes into a log you suspect has failed, because you are only opening new entry points for competitors while telling yourself you are helping.
Do not move the logs repeatedly. Each move risks knocking bark off, and bark damage during the spawn run is the injury that most often costs a log. If you must reposition a stack, carry the logs rather than dragging them, and keep them out of the sun during the move.
Above all, do not give up early. The most useful skill in the first year is the willingness to leave the logs alone. Mark the earliest date you would reasonably expect a flush in your notes, and simply do not evaluate the stack before then.