Southern Ag Aluminum Sulfate (Acidifies Soil), 5 LB Size: 5 LB 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. APPLICATION: Broadcast evenly, wash off foliage and water. For large quantity discount consideration or to request a mixed multi-pack, please message us.