• 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

Echinops ritro L.

Blue hedgehog

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
Blue hedgehog

© � RHS 2000

  • Other common names Blue hedgehog
    Globe flower

    Small globe thistle
    Steel globe thistle

    see more
  • Synonyms Echinops ritro 'Veitch's Blue' misapplied

  • Genus Echinops can be annuals, biennials or perennials with simple or pinnately lobed, spiny leaves and spherical blue or whitish flower-heads

  • Family Asteraceae / Asteraceae

  • Species E. ritro is a robust, upright herbaceous perennial, with jaggedy-divided, prickly dark green leaves whitish beneath. Rounded, violet-blue flower heads on silvery, branched, leafy stems

  • Plant range C&E Europe to C Asia

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

    H7

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Exposed

Soil

  • Chalk

    Sand

  • Chalk

    Loam

  • Chalk

    Chalk

  • MoistureWell-drained

  • SoilSand, Loam, Chalk

  • pHAcid, Alkaline, Neutral

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 Best in poor, well-drained soil in full sun but will tolerate most soils in full sun and can tolerate partial shade

Propagation Propagate by seed sown in seed bed in mid spring. Propagate by division in spring or autumn. Propagate by root cuttings in winter

Suggested planting locations and garden types Flower borders and beds Cut Flowers Low Maintenance Cottage & Informal Garden Wildlife Gardens Gravel Garden

How to care

Pruning Deadhead to prevent self-seeding

Pests Prone to aphids

Diseases Generally disease free

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