Greensand has been used as a soil amendment and conditioner since the early 1700s. Naturally occurring in marine sedimentary deposits, Down To Earth’s Greensand is composed primarily of the blue-green siliceous mineral glauconite, a rich source of Potash and Iron. Traditionally used to loosen heavy clay soil or to hold together loose sandy soils, DTE Greensand is able to absorb up to one-third its weight in water to improve the moisture holding capacity of garden soils and potting mixes. DTE Greensand is highly recommended for vegetables, fruits, herbs, lawns, ornamentals and all types of trees and shrubs. OMRI Listed for organic production.