Rhododendron simsii /ro.doˈdɛn.drɔn/
Common name: Florist's azalea · Indian azalea · Sims' azalea
Rhododendron simsii is an evergreen shrub native to East Asia, including China, Taiwan, Myanmar, Thailand, and Laos, where it grows in forests and on hillsides. It typically reaches 1–2 m in height, with hairy, elliptical leaves and showy funnel-shaped flowers in shades of red, pink, or white. It is one of the most important parents of the greenhouse azaleas sold worldwide as potted flowering plants, especially during the winter holiday season.
Care summary
Sun
Bright indirect light; light shade outdoors
Water
Keep evenly moist; use lime-free water
Soil
Acidic, peaty, well-drained
Hardiness
Zones 8–10
Mature height
About 100–200 cm (3–7 ft)
Pet safe
No — all parts toxic to cats and dogs
Difficulty
Fussy
Propagation
Propagate from semi-ripe cuttings taken in mid to late summer, treated with rooting hormone and kept in a humid, warm propagator with acidic, free-draining medium. Rooting takes several weeks to months, and young plants need cool, bright conditions.
Fun facts
- It was introduced to Europe in the early 19th century and named after John Sims, a British botanist and physician.
- Most of the potted "florist's azaleas" sold around Christmas and Chinese New Year trace back to this species.
- Unlike most rhododendrons, it is tender to frost and is usually grown as a houseplant or in warm climates.
- Azaleas like this one were formerly placed in their own genus but are now classified within Rhododendron.