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Dahlia 'Twyning's After Eight' (Sin) AGM

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© RHS

Characteristics

Plant type

Bedding

Habit

Bushy

Resilience

Hardiness

H3 (half hardy - unheated greenhouse/mild winter)

Colour

Flower

White in Autumn and Summer

Foliage

Black and Brown in Autumn, Spring and Summer

Size

Ultimate height

0.5-1 metres

Ultimate spread

0.5-1 metres

Time to ultimate height

1-2 years


Preferred common name

dahlia 'Twyning's After Eight'

Family

Asteraceae


Dahlia are tuberous rooted perennials with pinnately divided leaves and showy flower-heads, double in many cultivars, in summer and autumn

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

'Twyning's After Eight' grows to 1m, with very dark blackish-brown foliage and single white flowers 8cm across, with broad rays florets and a deep yellow central disk, opening from late summer

How to grow

Sunlight

  • Full sun

Aspect

  • South-facing or West-facing
  • Sheltered

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

Soil

  • Moist but well-drained
  • Acid, Alkaline or Neutral
  • Sand, Clay or Loam

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

City/Courtyard Gardens, Coastal, Cottage/Informal Garden, Flower borders and beds or Wall-side Borders


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

aphids, leaf miners, glasshouse red spider mite and slugs are common pests. Earwigs sometimes damage blooms. Capsid bug and caterpillars are occasional pests

Diseases

Powdery mildews can be damaging in dry conditions. In wet weather grey moulds and other fungal rots can be a problem. Fungal rots can also damage stored tubers. A virus may cause stunting, leaf markings and distortion