• 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 Happy Single Princess = 'Hs Princess' (PBR) (Happy Single Series) (Sin)

dahlia [Happy Single Princess]

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 [Happy Single Princess]

© RHS

  • Other common names dahlia [Happy Single Princess]

  • Family Asteraceae

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

  • Horticultural Group Single-flowered dahlias have flowerheads usually less than 10cm across, with one or two rows of spreading ray florets, surrounding a central boss of small tubular disc florets which are valuable for bees and butterflies

  • Details Happy Single Princess is a compact herbaceous perennial, to 80cm high, with leaves so dark they are almost black. Single flowers, 5cm across, with eight white rays, tinged with pink, and a golden yellow central disc, in summer and autumn

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)

    H3

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • Chalk

    Chalk

  • Sand

    Sand

  • Clay

    Clay

  • MoistureMoist but well-drained

  • SoilLoam, Chalk, Sand, Clay

  • 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 fertile, humus-rich, well-drained soil, enriched with organic matter, in full sun; lift and store tubers in autumn to replant or use as a source of cuttings in spring; poor flowering may be caused by overfeeding with high nitrogen fertilisers, not enough direct sunshine or not enough moisture at the roots; for more advice, see dahlia cultivation

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

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

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 May be affected by aphids, capsid bug, earwigs, caterpillars, slugs and glasshouse red spider mite

Diseases May be affected by powdery mildews, dahlia mosaic virus, cucumber mosaic virus, tomato spotted wilt virus, storage rots, and leafy gall

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