What are earthworm castings?

Worm castings are the excretions left behind by worms after they digest the organic matter that makes up their diet. They are comercailly available as a nutrient-dense organic amendment, or they are produced in your own yard by any earthworms naturally living there or cultivated in vermicompost. By adding nutrients to the soil, earthworm castings can greatly enhance plant growth. If used regularly in lawn care services, they can also help restore soil life and health in your yard. Since they add organic matter, castings can also help improve soil aeration and water retention capacity.