The large Portobello mushroom, also called a brown Crimini, has found its way into more than just Italian restaurants in recent years because of its nutty, full-bodied taste and excellent ability to hold together when it is cooked. They make a tasty, interesting addition to barbecued meals and are something that you can try to grow at home. Mushrooms do not grow in soil, but rather in a growing medium that is specific to the mushroom. The easiest way to grow Portobellos is to purchase a kit that contains the proper growing medium along with the mushroom spores.
Growing Portobello Mushrooms
Purchase a mushroom growing kit to keep it simple, since inoculating your own growing medium with Portobello mushroom spores is complicated, more expensive, and more prone to failure.
Set up your kit and be sure to follow instructions for the temperature and humidity you must maintain in your growing area during the "colonization" period, which is usually about 10 days. Typically, mushrooms require a temperature between 60 and 80 degrees Fahrenheit in order for the mycelia to grow.
Force fruiting of the mycelium by keeping the medium moist and the growing area totally dark. If you order a kit that includes a tent, this can help to retain the moisture this mushroom needs. Also spray daily with water that contains no chlorine.
Expect your growing kit to produce two or three "flushes" of mushrooms before the medium and the spores are depleted.
Put your depleted mushroom kit in your compost pile, where it might produce a few more mushrooms.