Growth from either spores or cloning tissue starts in sealed culture dishes (on the right). Started spawn (which may undergo an intermediate stage of growth in cooked grain) is then used to inoculate sterilized sawdust in sealed bags (on the left). Once the mycelium has thoroughly colonized the sawdust, it is far more capable of defending itself from threats in the environment, and is ready for sale to growers who do not maintain a clean room or work from sterile cultures.