The azalea is a showy perennial shrub that grows either as a deciduous azalea or an evergreen azalea. This plant grows large, deep-green-colored foliage and blooms colorful flowers during its growing season. Closely related, these flowers have no clear differentiation from rhododendrons and require the same care as these flowers.
Select a planting location for the azalea shrub. Choose a location that provides at least 6 hours of sunlight. The location should provide an ample amount of full morning sunlight with shaded sunlight for the remainder of the day.
Plant the azalea shrub in nutrient-rich, acidic soil with pH levels that rest between 5.5 and 6.0. Test the soil using a soil test packet before planting. Follow the soil test directions closely. Adjust the soil levels as necessary to reach the desired acidity requirements. Add sulfur or iron to the soil to increase acidity levels. Add ground limestone to decrease the soil's acidity levels.
Promote a well-drained soil environment. Till the soil thoroughly, incorporating an equal amount of organic material into the soil. Remove heavy soils from the planting area. Avoid using peat compost as this may promote excessive moisture in the azalea's planting area. Build an elevated soil bed for the azaleas so that the final environment rests 4 to 6 inches higher than the surrounding area.
Dig a hole for the azaleas that is slightly larger in height and equivalent in length to the ball of the azalea. Position the ball in the center of the hole so that it rests about 2 inches higher than the surrounding soil. Fill the hole with soil and press firmly to secure the azalea's position. Water the azalea thoroughly to promote a good establishment.
Cover the azalea's planting area with mulch to maintain moisture levels. Select decomposed oak leaves or shavings, pine needles, hardwood chips or sphagnum peat moss for mulching. Apply a layer of mulch that is at least 4 inches thick. Increase mulch thickness during the winter months to provide greater protection.
Avoid fertilizing newly planted azaleas. Complete a soil test in the early spring prior to fertilization. Apply a slow-release, acid-forming fertilizer only when the test results show a deficiency in the levels. Distribute the fertilizer evenly and lightly around the root zone of the azaleas. Use at half strength, a few tablespoons at a time.
Inspect the azalea shrub regularly for signs of insect infestation, especially the azalea lace bug. Look for black and white spots, black bugs, stunted growth and dieback. Treat infestations immediately to prevent irreversible damage. Use an insecticidal soap or insecticide that is designed for the lace bug and other insects.
Inspect the bush for signs of azalea petal blight, a common azalea fungal disease. Look for browning or yellowing of the plant, instability and short blooming periods. Treat diseased azaleas immediately using a fungicidal treatment. Speak with your local nursery or horticultural specialist for treatment and selection assistance.