Alum Uses In Gardens: Aluminum Soil Amendment Tips
Most plants do well with soil pH between 6.0 and 7.2 – either slightly acidic or slightly alkaline. However, some plants, including hydrangeas, azaleas, grapes, strawberries and blueberries, require more acidic soil. This is where alum comes in – aluminum sulfate can be used to lower soil pH, thus making the soil suitable for acid-loving ...