Americans consume about 4 pounds of mushrooms per person every year. Most of these mushrooms are raised by commercial mushroom growers, who raise their mushrooms in large warehouses or tunnels and produce thousands of pounds of fungi for sale to wholesalers. But even small growers can produce mushrooms for sales to local restaurants and at farmers markets.
Choose a Variety
Most commercial mushroom growers raise white button, cremini or Portobello mushrooms. One way to stand out in this crowded market would be to focus on unusual varieties of mushrooms, such as shitake mushrooms, oyster mushrooms or morels. These varieties appeal to gourmet diners and are not as readily available at supermarkets as the more common varieties are. Each type of mushroom has its specific growing requirements, so it’s easiest to focus on a single variety when you’re starting out.
Designate a Growing Space
Unlike most agricultural crops, mushrooms aren’t grown in fields. They're grown in enclosed spaces. They don’t need total darkness, but they like controlled humidity levels, and humidity is easier to maintain indoors. You can grow your mushrooms in a barn, a garage or other outbuilding or in a shady woodlot. Shitake mushrooms grow on old logs, so you’ll need a place to store the logs. Other types of mushrooms grow in beds or bags of compost or sawdust.
Acquire Your Growing Medium
You’ll need a source for compost, sawdust or other growing medium for your mushrooms. If you’re growing mushrooms on logs, you’ll have to buy logs or cut your own. The logs should be from hardwood trees. Any compost or sawdust you make or purchase needs to be sterilized with heat or by bleaching with hydrogen peroxide to kill any microorganisms that might contaminate your crop.
Inoculate Your Medium
Mushrooms grow from spawn, which you can purchase from a supplier. Mix the spawn with your compost or other medium, or inject it into holes drilled in your logs. Control the humidity and temperature as needed for the variety you’ve chosen to grow. Conventional bed mushrooms will start to produce in as little as three weeks, while log-grown shitakes take more than a year to produce.
Harvest and Market
Mushrooms decay quickly once they’re harvested, so you’ll want to have a market that's awaiting your new crop. Plan to deliver freshly harvested mushrooms right away to local restaurants, or offer them for sale at a farmers market the day of harvest. Harvesting mushrooms regularly during the growing period will encourage good production. You can preserve mushrooms for later sale by drying them.