Our 5 pound bags contain 100% pure worm castings. We feed our worms on our farm 1 year+ aged and chemical-free compost. Our castings are bagged with a perfect moisture content, always scent free, and permeating with microbes. Worm castings are a natural, organic fertilizer that contain a balanced mix of minerals and nutrients, including nitrogen, calcium, iron, magnesium, and sulfur. These nutrients are easily absorbed by plants, which can lead to faster growth, larger plants, better roots, and bigger blooms. This soil amendment is the black gold of gardening!