Hi-Yield Super Phosphate Dry Plant Food An inexpensive and effective source of phosphorous that plants and bulbs need to produce healthy roots, stems, and blooms. Application rate: Bulbs: Mix several tablespoons with soil when planting bulbs or small plants. For row planting: Mix 4 lb to each 50' evenly with loose soil in bottom of trench. Analysis: 0-18-0. 4 lb container.