• 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

Eryngium × oliverianum

Oliver eryngo

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
Oliver eryngo

© � RHS

  • Other common names Oliver eryngo

  • Genus Eryngium can be annuals, biennials or perennials with simple or divided leaves, often spiny edged, and cone-like flower-heads often surrounded by an involucre of conspicuous spiny bracts

  • Family Apiaceae / Apiaceae

  • Species E.oliverianum is an erect herbaceous perennial to 90cm, with strongly toothed, heart-shaped leaves and branching violet-blue stems bearing cone-like flowerheads surrounded by narrow, spiny, metallic-blue bracts

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

    H6

Colour

Sunlight

  • Full Sun

  • 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 Grow in dry, well-drained soil that is poor to moderately fertile. Full sun is essential as is protection from winter wet

Propagation Propagate by root cuttings in late winter

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

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