ferti•lome® Vermiculite is the mineral Mica, super-heated to expand much like an accordion. This mineral is also used in soil mixes to increase water-holding capacity. Many growers use vermiculite in their flats in order to create a microenvironment that will protect seeds from air currents and insulate the seeds to provide uniform germination temperatures. Can be used in potting mix aggregate, hydroponic media or as seed cover • Light weight • Insert • Neutral pH • Increase water retention • Sterile