• 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

Agrostemma githago 'Ocean Pearl'

corncockle 'Ocean Pearl'

corncockle 'Ocean Pearl'

© RHS

  • Other common names corncockle 'Ocean Pearl'

  • Family Caryophyllaceae

  • Genus Agrostemma are upright annuals with narrow, opposite leaves and solitary, 5-petalled, open trumpet-shaped flowers with long calyx lobes showing between the petals

  • Details 'Ocean Pearl' is a much-branched annual with narrow, greyish leaves and abundant, solitary white flowers, with fine dark speckling in the throat, in summer

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • Toxicity All parts, but particularly the seeds may cause severe discomfort 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)

    H5

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Sand

    Sand

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1 year

How to grow

Cultivation Grow in poor, well-drained soil in full sun. Lax growth needs to be staked, deadhead to prolong flowering. Flowers are suitable for cutting and are attractive to bees

Propagation Propagate by seed sown in-situ, self-seeds prolifically

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

How to care

Pruning Cut back after flowering

Pests Generally pest free

Diseases Generally disease free

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