Southern Ag Aluminum Sulfate Catalog Outdoor, Lawn & Garden Gardening Southern Ag Aluminum Sulfate Manufacturer : Southern Ag Description • Great for Hydrangeas • Acidifies Soil (lowers pH), corrects high alkalinity CONTAINS: Fertilizer grade aluminum sulfate, as metallic 9.0%.Not for spray application. USE ON: Acid loving shrubs like rhododendrons, hydrangeas, blueberries, dogwoods, holly, gardenias, camellias, and azaleas. CORRECTS: Excess alkalinity in the soil. RATE: For large shrubs: Use 1 lb. per 3 ft. of height. For trees: Use 1 lb. per inch of trunk diameter. For small shrubs: Use 5 lbs. per 100 sq. ft. APPLICATION: Broadcast evenly, wash off foliage and water. Rates Please contact us for current pricing and availability.