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Flame Azalea

Rhododendron calendulaceum

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Flame Azalea (Rhododendron calendulaceum) at Homestead Gardens

Flame Azalea flowers

Flame Azalea flowers

(Photo courtesy of NetPS Plant Finder)

Height:  15 feet

Spread:  15 feet

Sunlight:  full sun  partial shade 

Hardiness Zone:  5b

Description:

A spectacular native shrub of the Appalachian mountains, tends not to grow as tall under cultivation; the fiery orange blooms are very showy and larger than other natives; leaves are long and medium to dark green; grows best in rich acidic soil

Ornamental Features

Flame Azalea is blanketed in stunning clusters of orange trumpet-shaped flowers at the ends of the branches in mid spring, which emerge from distinctive shell pink flower buds before the leaves. It has dark green foliage throughout the season. The narrow leaves do not develop any appreciable fall color. The fruit is not ornamentally significant.

Landscape Attributes

Flame Azalea is an open multi-stemmed deciduous shrub with a more or less rounded form. Its relatively coarse texture can be used to stand it apart from other landscape plants with finer foliage.

This is a relatively low maintenance shrub, and should only be pruned after flowering to avoid removing any of the current season's flowers. It has no significant negative characteristics.

Flame Azalea is recommended for the following landscape applications;

  • Accent
  • Mass Planting
  • General Garden Use

Planting & Growing

Flame Azalea will grow to be about 15 feet tall at maturity, with a spread of 15 feet. It tends to be a little leggy, with a typical clearance of 1 foot from the ground, and is suitable for planting under power lines. It grows at a slow rate, and under ideal conditions can be expected to live for 40 years or more.

This shrub does best in full sun to partial shade. It requires an evenly moist well-drained soil for optimal growth, but will die in standing water. It is very fussy about its soil conditions and must have rich, acidic soils to ensure success, and is subject to chlorosis (yellowing) of the leaves in alkaline soils. It is somewhat tolerant of urban pollution, and will benefit from being planted in a relatively sheltered location. Consider applying a thick mulch around the root zone in winter to protect it in exposed locations or colder microclimates. This species is native to parts of North America.

 
 
Hardiness Zone Plant Height Minimum Sunlight Soil pH Preference
Characteristics
Accent  Massing  Garden 
Applications
Flowers  Winter Value 
Ornamental Features