SUPREME PERLITE Coarse Propagation Grade perlite consists of large, medium, and fine perlite grains intended to provide balanced drainage and moistureholding capacity. An excellent propagation medium on its own, it is also useful as a soil amendment, and conditioner for soilless growing media. Mix with coconut coir, peat moss, or other growing media to make a high quality potting mix. Perlite is a 100% natural, heat-expanded siliceous volcanic rock. It is used to loosen heavy soils and as a medium for seed starting and root cuttings. Perlite is, sterile, ultra-lightweight, non-toxic, permanent, incombustible, asbestos-free, and virtually pH-neutral. Our agricultural and horticultural grade products are listed with various standards organizations for organic agriculture including the Organic Materials Research Institute (OMRI) and the California Department of Agriculture's Organic Input Material Program (CDFA OIM). Organic certification ensures that our products are free of contamination from heavy metals and pathogens, and produced to the highest standard of purity and quality