Morel mushrooms belong to the Morchella genus, which contains at least six species. Cooks highly prize these mushrooms for their delicate, earthy flavor, especially in French cuisine. Morel mushrooms are difficult to grow on a large scale, so mushroom hunters meet commercial needs by harvesting wild morel mushrooms. Private gardeners also grow morel mushrooms indoors, although these mushrooms are slow to produce the fruiting bodies commonly known as caps.
Punch drainage holes in the bottom of a shallow metal tray such as a cake pan to use as a fruiting tray. Clean the tray with a 5 percent solution of bleach to sterilize the pan.
Prepare a substrate containing 50 percent organic compost, 30 percent potting soil and 20 percent sand. Add enough powdered limestone to this mixture to raise the soil pH to 7.2. Fill the trays to a depth of 2 inches with the substrate.
Soak the substrate with water and allow it to drain completely. Add the morel mushroom spawn to the substrate according to the manufacturer's instructions.
Place the fruiting tray indoors in a temperature-controlled growing room with no light. Maintain a temperature between 65 and 70 degrees Fahrenheit with at least 90 percent humidity. Hard lumps of mycelium known as schlerotia should form on the surface of the substrate in four to six weeks.
Refrigerate the fruiting tray at 39 degrees Fahrenheit for two weeks. Slowly add 2 oz. of water to the fruiting tray for every square foot of the tray's surface area. Allow the water to drain from the fruiting tray for a full day.
Place the fruiting tray back in the growing room. Keep the relative humidity of the room above 90 percent and maintain it at a temperature of about 72 degrees Fahrenheit. Use grow lights to provide 12 hours of light and 12 hours of darkness. The stalks of the morel mushrooms should appear within one week. Harvest the mushroom caps as they grow.