What Does an Azalea Bush Need to Survive?

Soil

• Fast-draining soil is critical for survival and healthy growth, as azaleas are shallow-rooted plants prone to rot and other diseases in consistently wet or soggy soil. Azaleas don't tolerate alkaline soil, performing best in acidic soil with a pH of 5.0 to 5.5. To determine soil pH, use a testing kit available at most garden centers and nurseries. To improve the pH of alkaline soil, increase acidity by digging in ferrous sulfate or agricultural sulfate. Add limestone if the soil is highly acidic, with a pH below 4.5. Azaleas also benefit from the addition of organic materials to the soil at planting time, such as composted bark or leaf mold.

Sunlight and Wind

• Azaleas prefer semi-shady areas with dappled or filtered sunlight. Harsh afternoon sunlight can damage the plant, but dense shade results in slow growth and decreased blooming. Although azaleas are cold tolerant, they don't grow well in harsh wind. The best location is a spot protected by a windbreak such as a building or slope. Otherwise, protect the shrub by planting evergreen trees or shrubs, especially to the west and south of the azalea. A light layer of leaves can protect the roots; however, don't apply a heavy layer because leaves become wet and compacted, preventing water and air from reaching the roots.

Fertilization

• Although azaleas require little attention once established, the plants benefit from fertilization in late spring. Don't feed the plant after midsummer, as a plant with tender new growth is more likely to suffer from cold during the winter. Use a dry, 6-10-4 fertilizer formulated for acid-loving plants -- regular fertilizer often lacks the best combination of nutrients for azaleas. Apply the fertilizer at a rate of 2 pounds for each 100 square feet of planting space, scattering evenly on the soil around the plant, not touching the trunk. Always water deeply after applying fertilizer to prevent scorching the shallow roots.

Water

• Azaleas require regular irrigation. However, they perform best if air circulates around the roots, which occurs when the soil is allowed to dry somewhat between waterings. Check the soil at the base of the bush to determine when your plants need water. If the top 3 to 4 inches of soil feel dry, provide enough water to wet the soil to a depth of 6 to 8 inches. Avoid overhead watering with sprinklers, as wetting the foliage places the plant at risk of disease. Instead, use a soaker hose or let a garden hose trickle slowly. A 2-inch layer of natural mulch such as bark chips keeps the roots cool and moist.