Perlite, made from volcanic rock, is a white, light weight material often used as a soil additive. The 1/8" to 1/4" pellets can be used alone as growing medium, but don't provide enough anchorage for large plants. Perlite is often used to start seed and cuttings, which can easily transplanted after rooting. Vermiculite is use the same way as Perlite, and the two are sometimes mixed together. It is made from heat expanded mica and has a flaky, shiny appearance. Soilless mix such as Pro-mix BX, and Pro-mix lite has the appearance and texture of light soil. Mainly peatmoss, mixed with Perlite, it contains very little nutrient, and is used a a soil additive, or alone as a hydroponic medium.
