• 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

Sorbus hybrida L. 'Gibbsii'

mountain ash 'Gibbsii'

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
mountain ash 'Gibbsii'

© � RHS 2002

  • Other common names mountain ash 'Gibbsii'

  • Genus Sorbus can be deciduous trees or shrubs with simple or pinnate leaves and clusters of small white or pink flowers, followed by white, yellow, pink, red or brown berries; some have fine autumn colour

  • Family Rosaceae / Rosaceae

  • Details 'Gibbsii' is a medium-sized deciduous tree with ascending main branches and a rounded crown bearing oblong leaves to 15cm, lobed with 1-2 pairs of free leaflets at base. White flowers are followed by globose, deep red fruits 12mm in length

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)
    Old hardiness ratings

    While we update our systems with the new hardiness ratings you may still see old hardiness ratings in your search results. These are denoted as 'Old'.

    • H1 - Requires heated glass
    • H2 - Requires unheated glass
    • H3 - Hardy outside in some regions of the UK
    • H4 - Hardy throughout the UK
    • H1 + H3 - Requires heated glass but may be grown outside in summer

    For full details of the hardiness ratings see

    see more

    H6

Colour

Sunlight

  • Full Sun

  • Partial Shade

  • Aspect South-facing or West-facing or East-facing

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Clay

  • Chalk

    Sand

  • Chalk

    Loam

  • Chalk

    Chalk

  • MoistureWell-drained, Moist but well-drained

  • SoilClay, Sand, Loam, Chalk

  • pHAcid, Neutral

Size

  • Ultimate height

    8-12 metres

  • Ultimate spread

    4-8 metres

  • Time to ultimate height

    20-50 years

How to grow

Cultivation Grow in moderately fertile, humus-rich soil. Tolerant of atmospheric pollution

Propagation Propagate by softwood cuttings in early summer, budding in summer or grafting in winter

Suggested planting locations and garden types Low Maintenance

How to care

Pruning Pruning group 1

Pests May be attacked by aphids, blister beetles, glasshouse red spider mite, scale insects and sawflies

Diseases Susceptible to silver leaf, honey fungus, fireblight and a canker

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