Do-it-yourself button mushrooms in the home and garden in just 30 days 1)Open the bag and press down the substrate firmly until the volume is halved. 2)Spread the soil evenly and cut away the surplus nylon. Place in an enclosed space (home, cellar, etc.) at a temperature of 16-24 °C. 3)Keep the soil damp with an atomiser spray, away from draughts and sunlight. The mushrooms will appear in 20-30 days.