Westland Fish, Blood and Bone is a good natural source of all three of the major nutrients. Nutrients are taken up efficiently due to longer period of release in the soil. Being especially high in phosphorus makes it particularly good for stimulating strong, healthy root growth. Features: Refillable tub Ready to use rich in essential nutrients Rich in trace elements for stronger plants 5 weeks nutrient release Increases crop yield High in phosphorus helps roots grow bigger and stronger Added calcium keeps your plant healthy and strong Helps build soil fertility.