A high quality, permanent, sterile additive with many uses. See the detailed description.
Vermiculite is the mineral Mica, super-heated to expand much like a accordion. This mineral is often used in soil mixes to increase water holding. Many growers use vermiculite in their flats in order to create a micro environment that will protect seeds from air currents and insulate the seeds to provide uniform germination temperatures.
Ferti-lome Horticultural Vermiculite: