Espoma Organic Earthworm Castings are 100% pure with no additives or fillers. Earthworms are fed a proprietary diet of exceptional natural and organic feedstocks. The result is a safe, non-toxic and all natural organic fertilizer and soil conditioner that produces vigorous plant and root growth while improving soil structure. Use on All Indoor & Outdoor Plants Grow Bigger, More Beautiful Plants Adds Organic Matter to Soils 100% Natural & Organic Approved Safe for People, Pets, and Planet