Not the plant you're looking for? Search over 300,000 plants
BeddingHerbaceous Perennial

Dahlia 'Starsister Red-yellow' (Col)
  • RHS Plants for pollinators

dahlia 'Starsister Red-yellow'

'Starsister Red-yellow' is a dwarf cultivar with green foliage that flowers in summer and early autumn. An inner collar of yellow petals are set around a golden-yellow eye and against an outer circle of red petals

Size
Ultimate height
0.1–0.5 metres
Time to ultimate height
1–2 years
Ultimate spread
0.1–0.5 metres
Growing conditions
Chalk
Clay
Loam
Sand
Moisture
Moist but well–drained
pH
Acid, Alkaline, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring
Summer Red Yellow Green
Autumn Red Yellow Green
Winter
Position
  • Full sun
Aspect

West–facing or South–facing or East–facing

Exposure
Sheltered
Hardiness
H3
Botanical details
Family
Asteraceae
Native to the UK
No
Foliage
Deciduous
Habit
Columnar upright
Potentially harmful
All parts may cause severe discomfort if ingested and may irritate skin. Wear gloves and other protective equipment when handling
Genus

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

Name status

Unresolved

Horticultural Group
Collerette-flowered dahlias have a single outer row of flat ray florets, with an inner ring of shorter florets surrounding the central disk florets

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. Water freely in dry periods. Lift and store tubers in autumn to replant or use as a source of cuttings in spring. See dahlia cultivation

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
  • Cottage and informal garden
  • City and courtyard gardens
  • Cut flowers
  • Flower borders and beds
Pruning

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

Pests

May be susceptible to aphids, capsid bug, earwigs, caterpillars and glasshouse red spider mite

Diseases

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

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.