• 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

Aesculus hippocastanum 'Baumannii' (d)

Baumann's horse chestnut

Baumann's horse chestnut

© RHS 2002

  • Other common names Baumann's horse chestnut

  • Synonyms Aesculus hippocastanum 'Flore Pleno'

  • Family Sapindaceae

  • Genus Aesculus can be deciduous trees or large shrubs with showy flowers, palmately-lobed leaves and sometimes good autumn colour

  • Details 'Baumannii' is a large, broad-crowned deciduous tree with large dark leaves of 5-7 leaflets. Flowers double, white with yellow marks that age to red. Fruit not developing

Characteristics

  • Foliage Deciduous

  • Habit Spreading / Branched

  • Toxicity Ingestion may cause severe discomfort

  • 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)

    H7

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered or Exposed

Soil

  • Chalk

    Chalk

  • Clay

    Clay

  • Sand

    Sand

  • Loam

    Loam

  • MoistureWell-drained, Moist but well-drained

  • SoilChalk, Clay, 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 Only suitable for large gardens; grow in deep, fertile, moist but well-drained soil in sun or part shade

Propagation Propagate by hardwood cuttings from early to midwinter or by chip budding from mid to late summer

Suggested planting locations and garden types Low Maintenance Architectural Cottage & Informal Garden

How to care

Pruning Pruning group 1

Pests Can get horse chestnut scale and leaf-mining moths

Diseases A canker, Coral spot and a leaf spot may be a problem

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