Fertilome Soil Acidifier Plus Iron 1 GallonDesigned to help reduce alkalinity in alkaline soils while supplying trace elements vital to acid loving plants such as Roses, Gardenias, Azaleas, Holly, Rhododendron, Magnolias, fruit trees and vegetables. Application Rate: Shake well before use and mix at rate of 2 tablespoons per gallon of water. Pour diluted mixture on ground over the root feeding area of the plant.