Conditions for Growing Morel Mushrooms

Poor Nutrients

• Most morel growers can produce healthy mycelium, the threadlike structure from which mushrooms grow, but have trouble getting the fungi to fruit. Sclerotia, the food-stage bodies that produce the actual mushroom, grow only when the growing medium is almost out of nutrients, according to the University of Wisconsin. One method of encouraging morels to fruit involves growing the mycelium in nutrient-poor substrate close to a rich source of nutrients. The mycelium transports nutrients back to the main fungus and begins to form sclerotia, which eventually produce mushrooms.

Moisture

• Fungi do not grow well in dry conditions. Morel mushrooms require damp, but not soggy, substrate to grow properly. The Farm, a Tennessee agricultural community, suggests saturating the growing substrate thoroughly, then allowing it to drain before inoculating it with mushroom spawn. Keep the relative humidity at 90 to 100 percent while the mycelium and sclerotia are growing. Saturate and drain the substrate again before fruiting is expected, and keep the substrate at about 60 percent moisture.

Temperature

• Morel mushrooms grow in the spring, after the ground has warmed and the danger of frost has passed. Chilling the substrate at temperatures near 40 degrees Fahrenheit for several weeks encourages the morel fungi to produce mushrooms. After chilling, allow the mushrooms to warm slowly and naturally to simulate spring-like conditions. The Farm suggests maintaining air temperatures between 65 and 70 degrees Fahrenheit initially, then increasing to between 70 and 73 degrees. Once fruiting bodies appear, increase temperatures to between 73 and 77 degrees.

Light

• Fungi prefer to grow in the dark but may need light to fruit successfully. Morels rely on light and dark cycles to prevent them from fruiting during a winter thaw. Providing 12 hours of light and 12 hours of darkness at a time encourages the mushrooms to grow. Keep the substrate in the dark until after chilling, then move to a 12-hour daylight cycle. If you're growing morels outside, natural light changes should provoke mushroom growth at the correct time of year.