• 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

Glaucium flavum

horned poppy

horned poppy

© RHS

  • Other common names horned poppy
    bruisewort

    caillichín na trá
    sea poppy
    seaside poppy
    yellow horned poppy

    see more
  • Synonyms Glaucium luteum

  • Family Papaveraceae

  • Genus Glaucium are erect, often rosette-forming, annuals, biennials and short-lived perennials with matt, blue-green or grey-green leaves and showy, poppy flowers

  • Details G. flavum is a short-lived perennial, usually grown as a biennial, forming a rosette of deeply-lobed, blue-green leaves. Branched, grey stems carry bright yellow or orange poppy flowers in summer, followed by long, narrow, upright seed pods

  • Plant range Europe Africa Asia

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • Toxicity Roots are toxic if ingested

  • 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)

    H4

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Sand

    Sand

  • Chalk

    Chalk

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Chalk, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1-2 years

How to grow

Cultivation Grow in poor to moderately fertile, well-drained soil in full sun. Resents root disturbance

Propagation Sow seed in situ in spring or autumn

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

How to care

Pruning No pruning needed

Pests Generally trouble free

Diseases Generally trouble free

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