Rhododendron calendulaceum

Flame Azalea




  • 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


  • 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


  • small capsules
  • not ornamental


  • not ornamentally important


  • 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


  • specific site and soil requirements

ID Features

  • multistemmed deciduous shrub with leaves appearing whorled at the tips
  • brilliant orange flowers
  • flowers non-fragrant


  • by cuttings
  • by seed


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.

© Copyright Mark H. Brand, 1997-2015.

The digital materials (images and text) available from the UConn Plant Database are protected by copyright. Public use via the Internet for non-profit and educational purposes is permitted. Use of the materials for profit is prohibited.

Citation and Acknowledgements: University of Connecticut Plant Database, http://hort.uconn.edu/plants, Mark H. Brand, Department of Plant Science and Landscape Architecture, Storrs, CT 06269-4067 USA.