My shiitake-innoculated log is still just a log, even though it is almost two years old. However, the log of my friend Susan (whose log is from the source, on the same day) is making mushrooms!
She says the secret may be "benign neglect." We had been told to "plant" the logs; she planted hers in a container, then stuck it in the shade under a holly. She then pretty much forgot about it, until a couple of weeks ago, when she noticed that it looked different.
I am so happy to see those mushrooms. They give me hope that my log, too, will someday burst with fungal fruiting bodies.