Log Management Following Spawn Run

 The mushroom organism (mycelium) that was introduced into the log last year has been busy establishing itself  in the sapwood of the log. This is called the spawn run.  During the spawn run the mycelium will colonize the sapwood of the log.  In Ontario this takes about 6 months depending on the hardness of the wood and environmental conditions. The spawn run will progress throughout the summer and fall.  You may see some mushrooms emerging in the fall.  Then, during the winter, the logs should remain in a low-profile stack under the forest canopy/in a shaded location exposed to rain and snow bput protected from direct sunlight.  Fruiting will likely begin the spring after inoculation. With proper handling and good management the logs should give you 4 to 5 years of production depending on the hardness of the wood, the diameter of the logs, and the integrity of the bark. The logs will produce mushrooms outdoors from May to November and can be fruited in a greenhouse during the winter months.
During the spawn run the logs should be stacked off the ground (on a skid for example) with space around each log such as in a ‘log cabin style pattern.  Logs should be located in a well-ventilated area, protected from direct sunlight, especially in the late afternoon period.  Do not stack logs in standing water such as a swampy area. During the spawn run logs must be prevented from drying out inside and from overheating. This can be achieved by stacking them in a shaded location and watering when necessary such as during a drought.  Shade can be natural, as under trees or bushes, or man-made, as under breathable shade cloth; or you can cover with boughs of cedar which will allow rain to soak the logs . Dehydration can be avoided by exposure to rainfall or by manually watering – sprinkling. 
Generally,  logs will fruit spontaneously in the spring following rainfall, producing a flush of mushrooms. At this point and throughout the harvesting season logs should be standing up, with one end on the ground (to allow moisture to be absorbed from the ground) and the other end leaning against a tree, or on rope, or wire that you can string between two trees or posts or logs can be leaned on split rails.  Logs can  be stacked and handled in various arrangements to allow the mushrooms to emerge without getting squashed or dirty and to facilitate harvesting.    
Logs can be managed casually and allowed to fruit spontaneously.  Or logs can be managed more intensively to get predictable fruitings.  This is called ‘forcing’.   Forcing is achieved by soaking/immersing the whole log in cold water for 6-18 hours. However, irrigation with a sprinkler for 24-48 hours also works. The logs can also be physically “shocked”. This can be achieved by dropping them to the ground or even by hitting with a hammer.   It is worth repeating that the log must be soaked for 24 to 48 hours and that the bark must then be allowed to dry out in a well-ventilated area and protected from prolonged periods of direct sunlight. Note that logs will float and in order to soak them in a tank or pond they must be completely immersed. This can be done in tanks with logs in metal cages so they won’t float.  For small scaled growers this can be done by immersing logs in containers filled with spring water such as a garbage can; weight with a stone or brick to keep t hem from popping up. If using chlorinated water it is best to allow the water to stand over night so that the chlorine off-gasses.  
The integrity of the bark must be maintained because it is the ‘skin’ of the log — it keeps moisture in and other organisms out. The bark is negatively affected by UV rays and by constant wet/dampness.  The outside of the log must be allowed to dry after soaking/sprinkling to prevent molds from growing on the bark which will result in de-barking.
 Approximately a week after soaking or irrigation the logs will start to “flush” with mushrooms. From the time you see little mushroom ‘pins’ coming out, to maturity, depends on the ambient temperature and humidity. Spring and fall growth is usually slow but summer fruitings can mature in a couple of days. Keep your eye on your logs. Shiitake  mushrooms should be harvested shortly after the veil has broken under the cap revealing the gills. Oyster mushrooms and Liion’s Mane mushrooms should be harvested after the clumps have formed when they are firm and before they become soft.  Mushrooms should be harvested when dry and not immediately after rainfall.  Wet mushrooms do not keep for long.  Oyster mushrooms are susceptible to infestation and should be harvested promptly.  Keep your eye on your logs!  to harvest you can cut from the log or simply grad the mushroom of clump and twist/pull them off.  
Following harvesting the logs should be left alone so the mycelium can re-energize itself by digesting more wood lignan. This means six to eight weeks rest and then the soaking/sprinkling can be repeated. Using this management regime the logs can produce 3 to 4 harvests per season yielding up to a total of 1 Kilogram of mushrooms per year.  Less frequent soakings, which allows time for the mycelium to store more nutrients between harvests, will generally produce larger mushrooms.   With proper care the logs will last an average of five years. Staggered soaking of groups of logs will spread production over your log population.
Youcan find detailed information about shiitake log inoculation and management in these books:
Growing Shiitake Mushrooms in a Continental Climate by Kozak,M. &  J. Krawcyk
Shiitake Grower’s Handbook by Przybylowicz, P. &  J.Donaghue          
These books may no longer be in print or may be difficult to obtain.  An excellent online source for detailed information about mushroom cultivation outdoors on hardwood logs is the Sustainable Agriculture Research Education (SARE.org) extension project at Cornell University. You can find the manual titled “Best Management Practices for Log-based Shiitake Cultivation in the Northeastern United States” that you can browse and download for free – second link below. 
Log-Based Shiitake Cultivation – SARE Northeast