• 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

Trollius × cultorum 'Superbus'

globeflower 'Superbus'

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
globeflower 'Superbus'

© � RHS 2003

  • Other common names globeflower 'Superbus'

  • Synonyms Trollius europaeus 'Superbus'

  • Genus Trollius are herbaceous perennials which form a clump of palmately lobed leaves, with erect stems bearing solitary, yellow, globose or bowl-shaped flowers composed of several petal-like sepals surrounding much-reduced nectar-bearing petals

  • Family Ranunculaceae / Ranunculaceae

  • Details 'Superbus' is a clump-forming herbaceous perennial to 60cm, with deeply divided basal leaves and long stems bearing globose, lemon-yellow flowers 5cm across

Characteristics

  • Foliage Deciduous

  • 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

    H7

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Loam

  • Chalk

    Clay

  • MoisturePoorly-drained

  • SoilLoam, Clay

  • pHNeutral, Acid, Alkaline

Size

  • Ultimate height

    0.5-1 metres

  • Ultimate spread

    0.1-0.5 metres

  • Time to ultimate height

    2-5 years

How to grow

Cultivation Grow in deep preferably heavy, moist soil that does not dry out, in full sun or partial shade. Cut back hard after flowering and apply a balanced liquid fertiliser to encourage further blooms.

Propagation Propagate by division in spring

Suggested planting locations and garden types Flower borders and beds Cottage & Informal Garden Wildflower meadow

How to care

Pruning Cut back hard after flowering

Pests Generally pest free

Diseases May be subject to powdery mildews

Advertise here

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now