Rhododendron calendulaceum
Flame Azalea
Ericaceae
ExpandHabitat
- cold hardy to zone 5
- performs poorly in zones warmer than 7
- native to the Appalachian Mountains form Pennsylvania to Georgia
Habit and Form
- a deciduous shrub
- multistemmed
- typically 4' to 10' in the landscape, but can reach 15' or so
- upright and spreading habit
Summer Foliage
- deciduous, simple leaves
- arrangement is alternate, but appears whorled towards the branch tips
- leaf shape is elliptic to ovate or obovate
- 1.25" to 3.5' long and 0.5' to 1.5" wide
- leaves tend to be pubescent when young and develop a glabrous upper surface when mature
- leaf color is medium to dark green
Autumn Foliage
- leaves turn a muted yellow to red
- not always dependable
Flowers
- very showy
- ranges from yellow, through orange, to red-orange
- tubular shape with 5 lobes
- flowers are 2" across
- in clusters
- bloom time is late May and early June
- not fragrant
Fruit
- small capsules
- not ornamental
Bark
- not ornamentally important
Culture
- full sun to light shade
- moist, cool acidic, well-drained soils high in organic matter are preferred
- avoid harsh, difficult sites
Landscape Use
- as a specimen
- shrub border
- naturalistic plantings
- effective in groups or masses
- useful for striking and showy orange blooms
Liabilities
- specific site and soil requirements
ID Features
- multistemmed deciduous shrub with leaves appearing whorled at the tips
- brilliant orange flowers
- flowers non-fragrant
Propagation
- by cuttings
- by seed
Cultivars/Varieties
Rhododendron calendulaceum has made its biggest impact as a parent in many azalea hybrids, such as the Ghent group. Color selections and hybrids of the species, however, are beginning to appear in the pages of catalogs dedicated to native trees and shrubs. Below are abbreviated descriptions of some forms.
'Chattooga' - A hybrid selection, this plant bears pink blooms with a yellow blotch.
'Cherokee' - This plant has flowers with apricot petals and yellow stamens.
'Golden Sunset Flame' - This plant bears blooms in a blend of shades with orange, yellow and gold.
'Golden Yellow Flame' - Large flowers with yellow petals and gold blotches adorn this selection.
'Smokey Mountaineer' - This is a compact grower with orange-red blooms and good red fall color.
'Wahsega' - This plant is notable for its dark red blooms.