Worm CastingsWorm castings are the waste of redworms, different from Vermicompost, which is soil worked by earthworms. Worm castings are amazingly rich in nitrogen, phosphates and other minerals. It is a powerful fertilizer and great for growing wheatgrass. Add 20% mix of worm castings to soil for a perfect growth medium. Various quantities of worm castings available for sale. Worm Castings Natural Soil Fertilizer for Gardens and Growing These worm castings come