Espoma Earthworm CastingsEspoma Orgainc Earthworm Castings are 100% pure with no fillers or additives. Earthworms are fed a proprietary blend of organic and natural feedstocks the results of which are a safe, non toxic, and all natural organic fertilizer and soil conditioner. A most excellent and natural way to promote vigorous plant and root development while improving soil structure. 4 qt 100% natural and organic approved Adds organic matter to soil Pet, people and planet