Greensand is mined from ancient, nutrient-rich deposits of oceanic sediment. Over time, this sediment developed into glauconite, which is highly effective as a slow-release fertilizer used to improve the mineral content of soil and other growing media. It is gentle on plants and won’t cause root burn. Recommended for use on lawns, household plants, golf courses, greenhouses, nurseries, and urban gardens. Suitable for all plants.