Be sure to use freshly cut hardwood logs that have been carefully prevented from any drying by the sun or wind. In my experience, the best time to cut the logs (I usually just use 6 inch thick branches so I don't fell any
trees) is in early spring right before the buds break open, If you are a beginner, it would be best to inoculate the logs heavily since Shiitake mycelium is so unagressive and can easily become contaminated. One method is to cut the logs to two foot lengths, then cover the cut ends with fresh spawn, then crimp heavy duty aluminum foil over the spawn. (You can also use a wax paper barrier in between the spawn and the aluminum foil if you are concerned about aluminum being absorbed by the mycelium.) I also cut wedges out along the length of the logs and apply fresh spawn to the wedge cuts. I then replace the wedges and wrap them with plastic wrap. I then place the logs in a big
cardboard box then cover them with super clean fresh sawdust from a hardwood mill and store the box in a 70 degree room that is free from insects (especially
ants!) or mold for 6 months. I have had good success with this method. In my experience, using dowel spawn and outdoor incubation has not been as successful a method, but it does work well for some growers. And be sure to read "Growing Shiitake Commercially" by Bob Harris.