Soil Amendment High In Nutrients 100% Natural Perfect Roses, Flower Beds, Garden Easy To Apply Worm castings are a natural soil amendment that are high in nutrients such as potassium, magnesium, calcium, and phosphorus. Made up of 100% natural worm manure, worm castings promote positive bacterial activity in the soil and help to stimulate healthy plant growth, protect your plants from diseases, and retain moisture in the soil while improving soil aeration. Worm castings also contain humic acid, which helps to free up nutrients in the soil and make them readily available to the plants in your garden, whereas manures and synthetic fertilizers need to be broken down before the plants can absorb the nutrients. Can be used in gardens, potted house plants, greenhouses, lawns, crops and fields.