How to Grow Everyday Mushrooms

Create a mushroom growing medium by composting chopped straw with horse or chicken manure. Soak straw in water for one day. Moisten the manure until it is saturated, but not liquefied. Drain the water from the straw. Use a garden fork to mix one part straw to one part manure.

Firm up the texture of the mixture by adding gypsum as you combine the ingredients. Mix and combine with gypsum until all ingredients are incorporated and the consistency of the mixture is no longer sticky. As a rule of thumb, add approximately 2 lbs. gypsum for every 4 ½ cubic feet of compost. Create your compost pile on a concrete pad to discourage pest infiltration from below.

Moisten the pile and cover to retain moisture when necessary. Periodically check the internal temperature of the pile. When the temperature reaches 160 to 170 degrees F, turn the pile inside out and moisten. Continue the process until the pile no longer emits an odor similar to ammonia—approximately five weeks.

Combine finished compost with mushroom spawn at a rate of 1 to 2 cups per mushroom tray. Fill the trays with compost, add spawn and mix until combined. Place the trays in a dark, well-ventilated area with a temperature between 65 and 70 degrees F. During the following weeks, a white, stringy fungus will colonize the surface of the mushroom trays. Keep the surface of the trays moist by lightly misting with a spray bottle.

Apply a layer or “case” of peat moss over the mushroom tray’s surface after it has become fully covered with white, stringy fungus. Moisten the peat moss until it clumps in your hand when compressed. Apply an even, 1-inch thick layer to the surface of each mushroom tray. Transfer the “cased” trays to an area with a temperature of 55 degrees F. Moisten, and keep moist, the layer of peat moss. In the following days, tiny dots will develop on the surface of the mushroom trays. The dots develop into mushrooms within approximately one week.