Native azaleas generally grow best in the climates in which they naturally evolved. Most species of azaleas native to North America evolved the southeast U.S. and will grow best in USDA Plant Hardiness Zones 6 to 8. You can click on your state and see what zone you live in: http://planthardiness.ars.usda.gov/PHZMWeb/#.
Azaleas do best in cool, partially shaded areas that are well-ventilated. Avoid long hours of direct sunlight as the azalea's foliage is susceptible to sunburn. On the other hand, too much shade can stunt the plants growth. It is important to make sure that your azalea tree is properly watered, especially during the dry summer months. To check the moisture level, place your finger 2 inches deep, if the soil feels moist near the top and dry toward the bottom, the azalea requires watering. If you notice your azalea needs fertilizer, be sure to choose a product that includes potassium, phosphorous and high levels of nitrogen.
Lastly, azaleas require highly acidic soils. The soil's pH balance should rest between 4.5 and 6.0. The soil should be well-drained and contain no levels of lime. Please let us know if you have any other questions.