• 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

Pterocarya fraxinifolia

Caucasian wingnut

Caucasian wingnut

© RHS

  • Other common names Caucasian wingnut
    Caucasian walnut

  • Family Juglandaceae

  • Genus Pterocarya are tall deciduous trees with large pinnate leaves and tiny flowers in pendulous catkins, followed by spikes of winged fruits

  • Details P. fraxinifolia is a vigorous, broadly spreading deciduous tree with large pinnate leaves and small green flowers in drooping racemes to 50cm long, followed by winged fruits

  • Plant range E Turkey, N Iran, Caucasus

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • 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

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Clay

    Clay

  • Sand

    Sand

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilClay, Sand, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height Higher than 12 metres

  • Ultimate spread wider than 8 metres

  • Time to ultimate height 20-50 years

How to grow

Cultivation Grow in deep, fertile, moist but well-drained soil in full sun

Propagation Propagate by seed in containers outdoors in autumn. Remove rooted suckers in autumn

Suggested planting locations and garden types Cottage & Informal Garden Architectural

How to care

Pruning Pruning group 1; remove unwanted suckers and seedlings as they appear

Pests Generally trouble free

Diseases Generally trouble free

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