Inoculation
The oak logs are cut in the winter, and then inoculated. Mycelium from the Shiitake mushroom is grown on sawdust under laboratory conditions to avoid cross contaimnation, and it is this mycelium laden sawdust that is pushed into holes drilled into the oak logs. A cap of wax is placed over each hole to prevent desication and stop the birds eating the sawdust! Then follows a period of 'benign neglect' This is called the spawn run and last for up to two years. In the photo you can see the white mycelium of the shiitake showing on the end grain of the log.
Fruiting
When the spawn run is complete, the logs are ready to fruit. We sell them from Ragmans at this stage. Please check with other suppliers if you are buying logs that are at point of fruiting, or whether you need to wait for up to two years for mushrooms. 'Shock' the logs to initiate fruiting by (i) knocking one end of the log sharply on hard ground and (ii) totally immersing it in COLD water (the icier the better!) for 48 hours. The water should be non-chlorinated, ie rainwater or tap water left to stand overnight. Place the log in a sheltered, shady spot and lightly cover with plastic to increase humidity, a shopping bag is ideal. Logs should start fruiting within 1 - 3 weeks, forming in 'flushes' (as in the photo). Remove the plastic cover once fruiting has started.
Picking
Cut the mushrooms off the log when the cap is 3 - 4 inches across, after 4 - 8 days of growing (they'll grow quicker in warmer temperatures). Shiitake have a brown cap and white gills - see the photos for positive identification. It's important to cut them off the log rather than picking them - this could reduce the chances of further fruitings. Trim off the stalks before eating.
Shiitake are best cooked slowly and gently - remember you are dealing with a vibrant fresh organic health food! You can also dry them (thread on a piece of string and leave in a dark airy place), and then reconstitute them when you are ready to use.
Resting
After picking the mushrooms leave the log outside on the earth in a damp place for two to three months to 'recuperate', then soak the log to start the second fruiting flush. Frost and snow are no problem. This resting period is for the mycelium to recolonise the sapwood of the log, and extract more nutrient for the shiitake mushrooms.
Winter and Summer
In Summer the log can be fruited successfully outdoors. In winter store the log outside, but fruit the log at room temperature after soaking and keep moist.
Extensive cultivation
It is also possible to simply leave the log outside in a shady place and it will fruit when the outside temperature is warm and wet. This is the easiest way of growing mushrooms, but not so productive and predictable! The log should fruit for up to six years.
You should look for a shaded, damp area sheltered from the wind. The log will need rainfall on it unless you are regularly soaking it. A north facing wall out of the wind is a good place, alternatively under a shady tree. Watch out for cats scratching and dog pee! Slugs can also be a problem - you may need to bring the log in to a slug free area while it is fruiting. The most important thing is to put the log somewhere easy to see! Most 'failures' are due to the log fruiting happily away at the bottom of the garden out of sight and mind.
Please note: DO NOT hang up the log - its handle is just for carrying!
The small print
Log cultivation of mushrooms is a practice that is subject to the whims of nature. With careful management, each log should produce around 2lbs of mushrooms over its lifetime, but success factors such as wind, temperature and humidity are uncontrollable. Log cultivation is not an exact science and requires patience, time and a little luck. Please persevere!
