• 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

Dahlia 'Bishop of Llandaff' (P)

dahlia 'Bishop of Llandaff'

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
  • Other common names dahlia 'Bishop of Llandaff'

  • Family Asteraceae

  • Genus Dahlia are tuberous rooted perennials with pinnately divided leaves and showy flowerheads, double in many cultivars, in summer and autumn

  • Details 'Bishop of Llandaff' is an herbaceous perennial to 1m in height, with deep blackish-red foliage and semi-double brilliant red flowers 6cm in width

Characteristics

  • Foliage Deciduous

  • Habit Columnar/Upright

  • Toxicity All parts may cause severe discomfort if ingested and may irritate skin

  • 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)

    H3

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • Clay

    Clay

  • Sand

    Sand

  • Chalk

    Chalk

  • MoistureMoist but well-drained

  • SoilLoam, Clay, Sand, Chalk

  • pHAcid, Neutral, Alkaline

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 fertile, humus-rich, well-drained soil, enriched with organic matter and general purpose fertiliser, in full sun. Pinch out growing tips to encourage bushy plants and stake. Water freely in dry periods. Lift and store tubers in autumn to replant or use as a source of cuttings in spring

Propagation Propagate by softwood cuttings taken in spring from shoots from stored tubers, or divide the tubers ensuring each division has a viable bud

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

How to care

Pruning Deadhead to prolong flowering. Cut back to near ground level in the autumn, before lifting and storing for the winter

Pests Can get aphids, capsid bug, earwigs, caterpillars and glasshouse red spider mite

Diseases May be affected by a virus, tubers may rot in store

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