• 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

Callistephus chinensis

China aster

  • Other common names China aster
    annual aster

  • Family Asteraceae

  • Genus Callistephus are bushy, upright annuals with coarsely toothed ovate leaves and large, solitary, daisy-like flower-heads, often double in cultivars, in late summer and autumn

  • Details C. chinensis varies in height from 20 to 70cm, and width from 25 to 45cm. Chrysanthemum-like flowers can be single, semi double or double, 7 to 12cm across and held on branching stems over a long period from late summer into autumn. Colours include light and dark purple, light and dark pink, red, yellow and white

  • Plant range China

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • 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)

    H2

Colour

Sunlight

  • Full Sun

  • Aspect West-facing or South-facing

  • Exposure Sheltered

Soil

  • Chalk

    Chalk

  • Clay

    Clay

  • Loam

    Loam

  • Sand

    Sand

  • MoistureMoist but well-drained

  • SoilChalk, Clay, Loam, Sand

  • pHAlkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1 year

How to grow

Cultivation Grow in a sheltered site in fertile, neutral to alkaline, moist but well-drained soil in full sun. Tall cultivars require staking

Propagation Propagate by seed sown at 16°C in early spring or in situ in mid-spring

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

How to care

Pruning Deadhead to prolong flowering

Pests Prone to aphids and cutworms

Diseases Prone to wilt diseases

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now

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.