Not the plant you're looking for? Search over 300,000 plants

Shrubs

Rhododendron simsii (EA)

Indian azalea

A tender evergreen or semi-evergreen azalea up to 2m high, with a branching habit and broadly ovate leaves. Produces funnel-shaped, carmine to rich red flowers, with darker red spots on the narrow petals, in pairs or small clusters at the tips of the stems in late spring. This species was a common parent for Indica hybrids

Synonyms

Azalea indica Sims

Save to My plants

Buy this plant

Plant nurseries
1 suppliers

Ultimate height

1.5–2.5 metres

Time to ultimate height

5–10 years

Ultimate spread

1.5–2.5 metres

Clay

Loam

Sand

Moisture

Moist but well–drained

pH

Acid

	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Partial shade

Aspect

North–facing or West–facing

Exposure

Sheltered

Hardiness
Hardiness ratings
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
H1a: under glass all year (>15C)
H1b: can be grown outside in the summer (10 - 15)
H1c: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20)

Botanical details

Family: Ericaceae
Native to GB / Ireland: No
Foliage: Evergreen or Semi evergreen
Habit: Spreading branched
Potentially harmful: Harmful if eaten. Wear gloves and other protective equipment when handling. Pets (dogs, cats, rabbits, tortoises) Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus: Rhododendron can be evergreen or deciduous shrubs or trees, with simple leaves, sometimes with a dense colourful indumentum of hairs on the lower side, and funnel-shaped, bell-shaped or tubular flowers that may be solitary or in short racemes
Name status: Correct
Horticultural Group: Evergreen azaleas are compact evergreen shrubs with small leaves and terminal racemes of small, funnel-shaped, usually unscented flowers in early summer
Plant range: Burma, Thailand, China

How to grow

Cultivation

May be grown outdoors in frost free areas, otherwise best grown under glass or in containers that can be moved indoors over winter. Grow in moist but well-drained, humus rich, acidic soil or in an ericaceous potting mix, and position in partial or dappled shade. See rhododendron cultivation for more detailed advice

Propagation

Propagate by semi-ripe cuttings in late summer, or by grafting in winter

Suggested planting locations and garden types

City and courtyard gardens
Cottage and informal garden
Patio and container plants
Conservatory and greenhouse
Flower borders and beds
Wall side borders

Pruning

Generally requires minimal pruning, though may need restrictive pruning if grown under glass; see pruning group 8 (evergreens). Deadhead if practical, to promote vegetative growth rather than seed production

Pests

May be susceptible to vine weevil, rhododendron and azalea whitefly, rhododendron leafhopper, Pieris lacebug, scale insects, caterpillars and aphids

Diseases

May be susceptible to powdery mildews, honey fungus, silver leaf and Phytophthora, as well as more specific Rhododendron diseases

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.