• 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

Delphinium 'Raymond Lister'

delphinium 'Raymond Lister'

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
delphinium 'Raymond Lister'

© RHS

  • Other common names delphinium 'Raymond Lister'

  • Family Ranunculaceae

  • Genus Delphinium can be annuals, biennials or perennials, with palmately lobed basal leaves and showy bowl-shaped flowers in spikes, racemes or panicles

  • Details 'Raymond Lister' is an erect, strong-growing, free-flowering herbaceous perennial, up to 1.7m high, with an equal balance between lobed green leaves and tapering spikes of brown-eyed, mid-blue flowers in midsummer

Characteristics

  • Foliage Deciduous

  • Habit Columnar/Upright

  • Toxicity Harmful if eaten

  • 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 Sheltered

Soil

  • Loam

    Loam

  • Chalk

    Chalk

  • Sand

    Sand

  • MoistureMoist but well-drained

  • SoilLoam, Chalk, Sand

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 1.5-2.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Grow in a fertile, well-drained soil in full sun; shelter from strong winds and provide stakes or other supports (see staking perennials)

Propagation Propagate by basal softwood cuttings in spring, or by division in early spring or early autumn

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

How to care

Pruning No pruning required except deadheading; cut stems down to ground level at the end of the growing season

Pests May be affected by aphids, earwigs, delphinium leaf miner, delphinium moth caterpillars, slugs, and snails

Diseases May be affected by powdery mildews, delphinium black blotch, grey moulds, sclerotinia disease, and cucumber mosaic virus

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