his bag contains what farmers refer to as “black gold”. There are no fillers here, only 100% pure earthworm castings certified for use in organic agriculture by Pro-Cert Organic Systems and OMRI listed. Our Earthworm Castings are screened to get out any large lumps and give you the perfect texture. Worm castings are the ideal soil amendment giving microbial life back to the soil structure and fertilizing boost.