• AGM plants

    AGM plants have been through a rigourous 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

Acer palmatum (Dissectum Group) 'Seiryu'

Japanese maple 'Seiryu'

AGM plants

AGM plants have been through a rigourous 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
Japanese maple 'Seiryu'

© � RHS 2000

  • Other common names Japanese maple 'Seiryu'

  • Synonyms Acer palmatum 'Seiry�'

  • Genus Acer can be deciduous trees or large shrubs with paired, often palmately-lobed leaves and small flowers followed by characteristic winged fruits. Many have fine autumn colour, and some have ornamental stems

  • Family Sapindaceae / Sapindaceae

  • Species 'Seiry?' is a medium-sized deciduous shrub of broadly columnar growth, with light green leaves, the lobes deeply incised; autumn colour orange, yellow and red. Flowers small, red

Characteristics

  • Foliage Deciduous

  • Habit Columnar_Upright#Columnar/Upright

  • 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

  • Partial Shade

  • Full Sun

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

  • Exposure Sheltered

Soil

  • Chalk

    Loam

  • Chalk

    Clay

  • Chalk

    Sand

  • Chalk

    Chalk

  • MoistureMoist but well-drained

  • SoilLoam, Clay, Sand, Chalk

  • pHAcid, Neutral

Size

  • Ultimate height

    2.5-4 metres

  • Ultimate spread

    2.5-4 metres

  • Time to ultimate height

    10-20 years

How to grow

Cultivation Grow in a moist but well-drained soil. Water in summer if necessary. Leaf colour is best in partial shade, although full sun can be tolerated. Leaf scorch can be caused by lack of soil moisture or excessive exposure

Propagation Propagate by grafting or softwood cuttings

Suggested planting locations and garden types Low Maintenance Architectural City & Courtyard Gardens Cottage & Informal Garden Patio & Container Plants Rock Garden

How to care

Pruning Pruning group 1

Pests Aphids and horse chestnut scale may be a problem

Diseases Verticillium wilt sometimes a problem

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