Of course, the meat of Growing Gourmet and Medicinal Mushrooms is information about how to take an existing mushroom and turn it into thousands of new mushrooms.  My previous lunchtime series about how to cultivate edible mushrooms for free explains most of the first step for turning an existing mushroom into a mass of mycelium (the vegetative growth form of the fungus.)  Basically, you can either choose to start with spores (like growing your mushroom from seed) or clone a mushroom you really like (like taking cuttings of a grape vine.)

The stem butt method of cloning was the one mentioned in Mycelium Running, and I have to admit that this method is a winner.  I managed to create a mass of mycelium this fall using oyster mushroom stem butts with nearly no effort.  Still, I've always interested in learning new techniques, and Growing Gourmet and Medicinal Mushrooms had a few in depth mushroom cloning tips.

First of all, it's best to start with a young mushroom in the button stage when cloning.  Also, I probably should have used only the inside of the stem butt since the outer portion is likely to be contaminated with competitor species, especially when cloning ground-fruiting mushrooms.  Other locations on the mushroom are just as useful for cloning, including the area just above the gills on the cap and the area on the stem right below the disk of the cap.