What Kind of Soil Does a Mushroom Need?

Common Mushrooms

• Common button mushrooms are members of the Agaricus mushroom family. Other members include crimini and portobello. Regular garden soil will not provide mushrooms with the rich nutrient-laden growth medium they require. Mushrooms do not depend on light to produce their carbohydrates. Instead, carbohydrates, sugars and nitrogen must be present within the growing medium. Create a nutrient-rich mushroom-growing medium by composting horse manure and straw. Turn the mixture every four to five days. Within several weeks the manure and straw will have decomposed to create a rich, earthy compost. This compost is heated to 140 degrees and placed in growing trays. The trays and medium are inoculated with mushroom spawn. The spawn spreads its filaments throughout the growing medium and, within a month, the first mushrooms are ready for harvest.

Shiitake Mushrooms

• In nature, shiitake mushrooms grow on wood. In cultivation, these growth mediums are recreated using a range of tree species. Oak, sweet gum, pecan, alder and beech are some of the wood varieties inoculated with shiitake mushroom spawn. The type of wood used affects mushroom flavor and growth rate. In the United States, growers tend to use white oak or sweet gum. Cut logs from healthy trees during their dormant season. Log diameters should be within 3 to 6 inches. Larger logs require more inoculations while smaller logs dry out prior to harvest. Nutrients and moisture from the log sustains mushroom growth. Inoculations should begin within two weeks of felling the tree. This timing ensures that adequate moisture is available to the mushroom spores.

Oyster Mushrooms

• Oyster mushrooms are grown from logs in much the same manner as shiitake mushrooms. An alternative to oak and other tree logs are artificial logs constructed from compressed sawdust, millet grain, rice bran or wheat bran. Shiitake mushrooms are also grown from these mediums. The benefit of artificial logs is their year-round availability. The downside is reports that mushroom flavor is diminished, according to a University of Kentucky crop profile report.

Corn Compost

• If growing common mushrooms from horse manure is unappealing, consider alternative composts for mushroom production. Corn compost is an aged mixture made up of corn fodder and hay. Combine equal amounts of hay with the ground corn cobs. Add leaf mold of peat moss for water retention and sand or granite dust for drainage. Well-aged compost can also be added to the mix. The mixture is placed in growing trees and inoculated with spawn. For large amounts, use 100 pounds of hay, 100 pounds of corn fodder, 20 pounds of peat moss and 30 pounds of sand. If you are interested in small-scale production, pre-made trays can be purchased from reputable catalogs and nurseries. These trays may also be pre-inoculated.