The Easiest Foolproof Method for Growing Mushrooms

Find a location that is dark, damp and cool. The Kansas State University Extension recommends monitoring the temperature in the potential location to be sure that it does not range far outside of 55 to 60 degrees Fahrenheit. Mushrooms can tolerate some light, but you should avoid locations with drafts or dry air.

Mix straw and horse manure to provide the growing medium. Turn it every four to five days, adding water to keep it moist when you do so. In about two weeks, it should be dark brown in color and without odor. Spread it into the tub and allow it to sit for one week.

Break spawn into pieces about one inch in diameter. Plant the spawn in the prepared tray, spacing pieces about eight to 10 inches apart, and planting them about two inches deep. For the next three weeks, keep the tray in the dark as much as possible and maintain the temperature at about 70 degrees Fahrenheit.

Cover the tray with one inch of good garden soil and lower the temperature to 60 degrees Fahrenheit. Water the tray whenever the top layer of soil begins to feel dry and powdery. The medium should remain moist but not wet. If you have trouble maintaining adequate humidity, the Kansas State University Extension recommends covering the tray with a layer or two of moistened burlap. Mushrooms will begin to appear in about three weeks.

Harvest mushrooms when the cap splits from the stem. Break or cut the stem at the soil surface; don't pull the mushrooms out of the soil, as you may disturb others just beginning to grow.