It is used throughout the world as a component of soil less growing mixes where it provides aeration and optimum moisture retention for superior plant growth. For rooting cuttings, 100% perlite is used. Studies have shown that outstanding yields are achieved with perlite hydroponics systems. It is a unique volcanic mineral which expands to about 13 times its original volume when it is heated to a temperature of approximately 1600 degree Fahrenheit (871 degree Celsius). During the heating process, the mineral particles pop like popcorn and form a granular, snow-white material that is so light in weight it weighs about 5 to 8 pounds per cubic foot (80-128 kg/cu. meter). Each particle of perlite is comprised of tiny closed air cells or bubbles. The surface of each particle is covered with tiny cavities which provide an extremely large surface area. These surface cavities trap moisture and make it available to plant roots. In addition, because of the physical shape of each particle of perlite, air passages are formed in the growing media thereby providing excellent aeration. Advantages of perlite are clean, odorless, and safe to handle, sterile, free of weeds and disease. It serves as an insulator to reduce extreme soil temperature fluctuations and makes moisture and nutrients readily available to plants. Other benefits of horticultural perlite are its neutral pH and the fact that it is sterile and weed-free. In addition, its light weight makes it ideal for use in container growing. Perlite is use as a carrier for fertilizer, herbicides and pesticides and for palletizing seed. Perlite is as useful to the home gardener as it is to the commercial grower. It is used with equal success in greenhouse growing, landscaping applications and in the home in house plants.
