Mountain Gate Organics Earthworm CastingsThese earthworm castings are from earthworms fed an organic, plant based diet to ensure pathogens are not transmitted from the host to the plants. Worm castings are rich in microorganisms which add nutrients to your soil and in return promote vigorous plant growth, vibrant color, increased crop yield, improved drainage, increased water retention, and the ability to ward off pests, fungus, and other diseases.