Azaleas are a subgenus of flowering shrubs that can grow up to 6 feet in height and produce numerous large flowers in colors of pink, purple, red or white. They bloom during the spring and can be deciduous or evergreen, depending on the species. Azalea bushes have a long lifespan with proper care, as some plants can live for as long as 50 years. Azalea bushes require only routine maintenance to survive in most temperate climates around the world.