Azaleas love peat moss added to their soil at planting time as this not only creates a more acid soil but also holds more moisture. A mulch of wood chips or bark chips on top of the soil will also make azaleas happy and keep the soil moist especially the first summer as they are building roots. Aluminum sulfate, soybean meal and cottonseed meal are all natural products used to make the soil more acidic. Apply as you would a fertilizer by sprinkling around the base of the plants about one cup per plant per year. Keep growing, Marianne Binetti