Purchase a kit or sterilized substrate, usually packaged in a plastic bag. If you prefer not to use a kit, you can purchase the substrate, usually a mixture of sawdust and grain bran, and inoculate it with mycelia yourself. It is very important that the substrate be sterile, and sterilizing your own requires expensive equipment and a controlled environment.
Inoculate the substrate by injecting the mycelia into it.
Incubate the bag of inoculated substrate at 70 to 75 degrees Fahrenheit and 95- to 100-percent humidity for 10 to 14 days. Keep it in a bright spot, but out of direct light.
Mist regularly with water to keep the humidity levels high.
Harvest lion's mane about once every 14 days when growing conditions are ideal.