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Rhododendron arborescens (A)

smooth azalea

A large, upright deciduous shrub with glossy mid-green leaves turning reddish-green in autumn. Strongly-scented, funnel-shaped white, pink-flushed flowers with red stamens are borne in early summer

Other common names
sweet azalea
tree azalea
Synonyms
Rhododendron 'Arborescens'
Azalea arborescens
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Size
Ultimate height
2.5–4 metres
Time to ultimate height
10–20 years
Ultimate spread
2.5–4 metres
Growing conditions
Clay
Loam
Sand
Moisture
Moist but well–drained
pH
Acid
Colour & scent
StemFlowerFoliageFruit
Spring Green
Summer White Green
Autumn Orange Purple Red
Winter
Position
  • Full sun
  • Partial shade
Aspect

North–facing or West–facing or South–facing or East–facing

Exposure
Sheltered
Hardiness
H6
Botanical details
Family
Ericaceae
Native to GB / Ireland
No
Foliage
Deciduous
Habit
Bushy
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
Azaleas can be deciduous or evergreen, with mostly small, frequently fragrant, funnel-shaped flowers in spring or early summer; deciduous azaleas often have good autumn colour
Plant range
Eastern N America

How to grow

Cultivation

Suitable for an open site but best grown in moist but well-drained, leafy, humus-rich acid soil in part shade with shelter; see rhododendron cultivation

Propagation

Propagate by seed when ripe, or semi-ripe cuttings in late summer, layering in autumn or grafting in late summer or late winter

Suggested planting locations and garden types
  • Coastal
  • Cottage and informal garden
  • Hedging and screens
Pruning

Pruning group 1

Pests

May be susceptible to vine weevil, rhododendron leafhopper, pieris lacebug, scale insects, caterpillars and aphids

Diseases

May be susceptible to various Rhododendron diseases including powdery mildews, rhododendron petal blight, rhododendron bud blast, silver leaf and honey fungus

Get involved

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