Vermiculite increases the friability of soil, making it easier for roots and root crops to grow. Add it to potting mix and garden beds to improve aeration while retaining moisture and nutrients. Vermiculite is a natural puffed mineral approved for organic gardening. It is an essential component of 'Mel's Mix' in Square Foot Gardening (1/3 vermiculite, 1/3 peat moss, and 1/3 compost). 1 cubic foot lightens a 2'x4' section of garden bed (6" deep). Sold in 1 cubic foot bags.