Mushrooms are one of those plants that most people would never think of growing. They are grown in conditions rather different than your normal garden variety plant. However, as long as few conditions are met, you can grow your own mushrooms without too much difficulty.
You need a rich compost of straw and manure that has been allowed to decompose for a couple of weeks. Keep the pile watered and turn it every few days, then bring it indoors. Continue the process for another couple of weeks until the pile has turned a dark brown color.
This is the stage where you inoculate the compost with the spawn of the type of mushroom you wish to grow. Make sure the pile is no longer hot and that there is no smell of ammonia--both indicators that the composting has not finished. Mix the spawn throughout the whole pile of compost.
Apply a casing layer to a depth of about eight inches. The casing layer can be as simple as wet paper pulp or wet peat moss. Even though the compost has been spawned, the mushrooms will not develop without this layer.
Start harvesting button mushrooms, for example, within just a few days of applying the casing layer. The harvesting will continue for almost six weeks, so you will have plenty of mushrooms even if you pick all the ones you can see.