Bella mushrooms are more commonly known as portabella mushrooms. A popular item in pasta sauces and recipes, the portabella mushroom is grown in much the same manner as the white mushroom. It is allowed to blossom for an additional three to seven days, giving it a much larger cap than the white mushroom. Portabella mushrooms reach up to 6 inches in diameter. They can be grown outdoors in the right climate, but cultivate indoors everywhere.
Place compost in a shallow tray. Choose a location for the tray that is moist and humid with warm conditions. Allow the compost to reach 150 degrees F in a dark location. Sustain this temperature for two hours then introduce cool air to produce oxygen in the soil.
Lay mycelium in rows just under the surface of the compost. Water generously. Maintain a temperature of 72 degrees F to promote germination of the mycelium. It will spread throughout the compost. This process will last 12 to 20 days.
Apply a thin layer of casing over the compost. Mix one part lime with one part peat moss and apply. This does not add nutrients to the compost, but helps retain moisture. Continue to maintain the temperature at 72 degrees for an additional five days.
Keep the compost moist. Harvestable portabella mushrooms will be produced in 18 to 21 days after the casing has been applied.