GAIA GREEN 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. Greensand is gentle on plants and won�t cause root burn. Greensand is recommended for use on lawns, household plants, golf courses, greenhouses, nurseries, and urban gardens, and is suitable for all plants.