• 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

Phormium cookianum subsp. hookeri 'Tricolor' (v)

mountain flax 'Tricolor'

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 flax 'Tricolor'

© � RHS 2002

  • Other common names mountain flax 'Tricolor'

  • Synonyms Phormium cookianum 'Tricolor'

  • Genus Phormium are evergreen perennials, making a large clump of leathery, strap-shaped leaves, with tall panicles of small, tubular flowers in summer

  • Family Hemerocallidaceae / Hemerocallidaceae

  • Details 'Tricolor' is an evergreen perennial making a large clump of sword-shaped leaves striped with yellow and green, edged with red. Flowers yellowish-green, in large panicles appear on mature plants in summer

Characteristics

  • Foliage Evergreen

  • Habit Clump-forming

  • 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

    H4

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or East-facing

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Clay

  • Chalk

    Loam

  • Chalk

    Chalk

  • Chalk

    Sand

  • MoistureWell-drained, Moist but well-drained

  • SoilClay, Loam, Chalk, Sand

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height

    1-1.5 metres

  • Ultimate spread

    1.5-2.5 metres

  • Time to ultimate height

    5-10 years

How to grow

Cultivation Grow in fertile, moist but well-drained soil in full sun. In frost-prone areas, provide a deep, dry mulch in winter

Propagation Propagate by division in spring

Suggested planting locations and garden types Flower borders and beds Low Maintenance Architectural City & Courtyard Gardens Cottage & Informal Garden

How to care

Pruning Deadhead in autumn to prevent winter rocking which can damage the plant

Pests May be attacked by mealybugs

Diseases Generally disease free

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