Flame Azalea Plant Care
Rhododendron calendulaceum (Michx.) Torr.
Rhododendron calendulaceum, the flame azalea, is a species of Rhododendron. It is a deciduous shrub that grows up to 120–450 cm tall.
Every 7–14 days
Partial shade to full sun
40–70°F
40–60%
What Is the Flame Azalea?
Flame Azalea (Rhododendron calendulaceum) belongs to the Ericaceae family within the Rhododendron genus. Flame Azalea is native to the Appalachian Mountains in the eastern United States, ranging from southern Pennsylvania and Ohio to northern Georgia. Flame Azalea is also known as Mountain Azalea, Piedmont Azalea.
Flame Azalea displays an upright, spreading shrub growth habit, reaching up to 6 inches tall with a spread of approximately 6 inches. Flame Azalea produces showy clusters of large, colorful blooms in various shades.
Leaf size: approximately 6 inches.
How Often Should You Water a Flame Azalea?
Rhododendron calendulaceum requires watering every 7–14 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–14 days
Let soil partially dry between waterings
What Light Does the Flame Azalea Need?
Flame Azalea thrives in partial shade to full sun light conditions. The optimal light range is 1000–3000 lux. Avoid placing Flame Azalea in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Partial shade to full sun
1000–3000 lux
What Temperature and Humidity Does the Flame Azalea Prefer?
Rhododendron calendulaceum grows best at temperatures between 40°F and 70°F. Flame Azalea prefers humidity levels of 40–60%.
Temperature
40–70°F
Humidity
40–60%
What Soil Mix Works Best for a Flame Azalea?
Well-draining, acidic soil with high organic matter content such as peat moss, pine bark, and perlite. Good drainage is essential for Flame Azalea to prevent waterlogging, which leads to root rot and fungal issues.
How Do You Repot a Flame Azalea?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Flame Azalea?
Flame Azalea can be propagated through stem cuttings, layering, grafting. Similar propagation techniques also apply to rhododendron plant care, which shares the same genus.
Fertilizing
Every 6 months
During the growing season
Is the Flame Azalea Toxic to Pets and Children?
Toxic to Pets & Children
Toxic to humans and pets if ingested
What Pests and Diseases Affect the Flame Azalea?
Flame Azalea is susceptible to aphids, lace bugs, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
What USDA Hardiness Zone Does the Flame Azalea Need?
Flame Azalea grows outdoors in USDA Zone 11a. Native to the Appalachian Mountains in the eastern United States, ranging from southern Pennsylvania and Ohio to northern Georgia, Flame Azalea is adapted to warm climates. In cooler regions, grow Flame Azalea as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 11a
Keep exploring plants
Flame Azalea is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Rhododendron genus — compare its care with other Rhododendron species on PlantoScan.
Flame Azalea tolerates low-light rooms and shaded spots — browse the full list of low-light plants.
More Rhododendron Species
Other Rhododendron species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Identify Plants Like the
Flame Azalea Instantly
Scan any plant with your iPhone camera and get instant ID, care tips, watering reminders, and disease checks — all in one app.
Free
to download
89%
accuracy
5.0
App Store
200K+
species