Unless you’re a researcher approved by the FDA to conduct research on psilocybin or you’re a part of Oregon’s fledgling medicinal psilocybin program, cultivating psychedelic mushrooms in the United States is illegal. In fact, in most places in the US, it carries significant jail time. Magic mushroom cultivation is legal in Austria, The Bahamas, Brazil, the British Virgin Islands, Jamaica, Nepal, Peru, and Samoa. This article in no way promotes cultivation of psychedelic mushrooms.
That said, the cultivation process is similar to growing other species of mushrooms, and it begins with compost. The makeup of that compost may vary, but it usually contains a mixture of damp, decaying material. Both currently and historically, manure has been a common choice in the mix.
Once that compost has broken down sufficiently, mushroom growers will put the material through a second round of composting that will use heat to pasteurize the material and kill unwanted organisms.
Next, mushroom spores need to be spawned into mycelium. This can be done by sterilizing grain and placing it into a sterilized container and then exposing it to mushroom spores. With the container sealed to prevent unwanted spores and microorganisms, the spores are given the chance to grow into mycelium and spread.
Once the grain is overtaken by the mycelium, it is called spawn. Spawn can be spread out over the compost and given a chance to grow throughout.
After the spawn has spread throughout the top layer of the compost, a new layer called casing is spread over the top. It usually contains a mixture of peat moss and vermiculite. This is the layer that mushrooms will eventually grow on.
After a few weeks, the first tiny mushrooms should start to appear. This phase is called pinning, since the first sprouts look like small pins. The carbon dioxide content in the growth environment will determine when this occurs, but it usually happens with a very low concentration of carbon dioxide. Once the pins start to appear, it’s time to introduce fresh air.
Finally, the mushrooms will continue to grow and develop into the familiar fungus on the surface. Once they’re fully grown, they’re ready for harvest.
This broad overview applies to many species of mushrooms, and is not intended to be a guide on how to break the law. Leave the cultivation and scientific exploration to the legally backed experts.