Plugging with dowel spawn: Inoculating with dowel spawn (birch dowels used by furniture makers overgrown with mycelium) is faster than with sawdust spawn—just tap the dowels into the holes with a hammer. But dowel spawn is not available from all suppliers, is more expensive, and requires a bit of a different size for drilling the holes. In my experience, dowel and sawdust spawn make an equally good start if given proper care following inoculation.