Vermiculite is one of the most popular & efficient soil conditioners. Safe and easy to use in almost any application. An all natural way to loosen soil, provide aeration and allow plants to retain water more effectively. Can be used to assist with seed starting or to propagate cuttings. Vermiculite is a natural volcanic mineral in fine granular form. One 18qt bag will cover .6 cubic feet.   Product Details: Fine Granular pellets loosens soil and provides aeration soil conditioner covers .6 cubic feet