• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

Rhododendron luteum (A)

yellow azalea

  • Other common names yellow azalea
    sweet pontica azalea

  • Family Ericaceae

  • 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

  • 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

  • Details R. luteum is a bushy deciduous shrub of open growth to 4m tall, with oblong leaves turning orange, purple and red in autumn. Very fragrant bright yellow, funnel-shaped flowers, 5cm in width, are produced in late spring and early summer

  • Plant range E Europe to Caucasus

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • Fragrance Flower

  • 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)

    H6

Colour

Sunlight

  • Full Sun

  • Partial Shade

  • Aspect North-facing or East-facing or West-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • Sand

    Sand

  • MoistureMoist but well-drained

  • SoilLoam, Sand

  • pHAcid

Size

  • Ultimate height 2.5-4 metres

  • Ultimate spread 2.5-4 metres

  • Time to ultimate height 10-20 years

How to grow

Cultivation This plant is listed on Schedule 9 of the UK Wildlife & Countryside Act as an invasive non-native species. While this does not prevent it from being sold in the UK, or from being grown in gardens, the RHS encourages those that do grow it to take great care with managing it and with disposing of unwanted material. The RHS also encourages gardeners to find alternative plants to grow to those listed on Schedule 9. For suggested alternative plants see the Plantlife/RHS guide: Gardening without harmful invasive plants

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 Hedging & Screens Wildlife Gardens Cottage & Informal Garden

How to care

Pruning Pruning group 1

Pests May be attacked by vine weevil, rhododendron leafhopper, pieris lacebug, scale insects, caterpillars and aphids

Diseases May be affected by various Rhododendron diseases including powdery mildews, rhododendron petal blight, rhododendron bud blast, silver leaf and honey fungus

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