Vermiculite is produced by heating a mica-like mineral. It is a sterile material that has the ability to retain moisture in the soil and also contributes to good aeration. It can be used pure or mixed with peat, sand, or soil. It is mainly used for covering in connection with seed sowing. When mixed with peat and soil, it provides a light and warm soil. Neutral pH. Size: 1-2 mm Sold in packages of 3 liters.