Perlite – A type of volcanic rock with high porosity that improves aeration & drainage in soil mixture
The development of near ideal structural conditions in growing and propagating media is made possible by the following characteristics of horticultural Perlite:
1) Improves aeration and drainage of the soil mixture.
2) Store moisture and nutrients for plants.
3) Is inorganic and does not deteriorate.
4) Has essentially neutral pH of 6.5 to 7.5.
5) Serves as an insulator to reduce extreme soil temperature fluctuations.
6) Is sterile and free of weeds and disease.
Perlite is a white volcanic glass and a derivative of silica. It expands 13 times its original volume when it is heated to 1,700°F. It weighs 80-128 kg per cubic meter.
Each particle of Perlite is comprised of tiny closed air cells or bubbles. It provides extremely large surface area. The surface of each particle is covered with tiny cavities. These surface trap moisture and make it available to plant roots and to the stems of cuttings. In addition, because of the phytical shape of each Perlite particle, air passages are formed in the growing mixture providing optimum aeration.