Deciduous Azalea Varieties

USDA Zones 3 and 4

• Native to southern parts of Quebec and much of the eastern United States, rose shell azalea (Rhododendron prinophyllum) grows to between 4 to 8 feet high in USDA zones 3 and 4. Adapted for cold weather, rose shell azalea generates pink flowers in April or May, often before its leaves emerge. Golden lights is another cold hardy azalea shrub, developed as a hybrid at the University of Minnesota, according to the Missouri Botanical Garden. Yellow flowers in May are the highlight of this 3- to 6-foot azalea that prospers in the shade.

USDA Zone 5 and 6

• The pinxter flower azalea (Rhododendron periclymenoides) grows in thickets, swamp edges and high-ground sites from the middle of New England south to Georgia and westward to most of the Midwest. It is a multi-stemmed shrub maturing between 4 to 6 feet tall and develops bright green foliage that turns dull yellow in fall. Appropriate for USDA zones 5 and 6, pinxter flower azalea produces pink flowers in May. Zones 5 and 6 are great venues for the flame azalea (Rhododendron calendulaceum), since this deciduous shrub does poorly in hot climates. The flowers are shades of red, yellow and orange, while the leaves change from green to yellow and red on this species, which reaches 15 feet in height.

USDA Zone 7

• Most royal azaleas (Rhododendron schlipenbachii) are from 5 to 7 feet high, but some of these Japanese and Korean Peninsula shrubs reach 15 feet in height. Suitable for USDA zone 7, royal azaleas feature a rounded form, with its fall foliage quite showy when it turns red, orange and yellow colors. The flowers bloom during the middle of May and are light pink. Florida, Alabama, Georgia and Mississippi are the haunts of the Florida azalea (Rhododendron austrinum). Best grown in partial shade, Florida azaleas generate flowers that vary from peach to yellow to a reddish-orange hue.

USDA Zone 8 and 9

• Mountain azalea (Rhododendron canescens) is a native plant species that grows from the Carolinas south to Florida and west to Texas. It works well in the heat and humidity of USDA zones 8 and 9, growing to 15 feet in partly shady spots, such as along foundations or in woodland gardens. Poukhanense (Rhododendron yedoense) is a Korean azalea that grows 6 feet tall but spreads out as much as 15 feet. The shrub produces rose-purple blooms in April and May, working well alone as a plant to highlight a shady area.