• 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

Cosmos bipinnatus Cupcakes Mixed

cosmea [Cupcakes Mixed]

cosmea [Cupcakes Mixed]

© RHS

  • Other common names cosmea [Cupcakes Mixed]

  • Family Asteraceae

  • Genus Cosmos can be annuals or perennials with simple or pinnately divided leaves and large, long-stalked daisy-like flowers in summer

  • Details Cupcakes Mixed are erect, bushy annuals up to 90cm high, with very finely-divided green leaves and flowers from about midsummer to the first frost. The distinctive flowers, 10-12 cm across, have the outer rays fused together around the yellow centre to form a bowl; the flowers may be single or semi-double, and the outer rays may be white, pale pink, or pink with darker pink at the base

Characteristics

  • Foliage Deciduous

  • Habit Columnar/Upright

  • 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 or East-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • Chalk

    Chalk

  • Sand

    Sand

  • Clay

    Clay

  • MoistureMoist but well-drained

  • SoilLoam, Chalk, Sand, Clay

  • pHNeutral, Acid, 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 Sow seed in spring and plant out from early summer, at 50cm spacing, in moist but well-drained soil in full sun

Propagation Propagate by seed in mid-spring: sow at 18-22°C, cover lightly with vermiculite, after germination reduce the heat to 10-15°C, and plant out when any risk of frost is over

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

How to care

Pruning No pruning required except deadheading to prolong the flowering season

Pests May be affected by aphids

Diseases May be affected by grey moulds

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