• 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

Hibiscus rosa-sinensis 'Cooperi' (v)

rose mallow 'Cooperi'

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
  • Other common names rose mallow 'Cooperi'

  • Family Malvaceae

  • Genus Hibiscus can be deciduous or evergreen shrubs, trees, annuals or perennials, with simple or palmately lobed leaves and large, funnel-shaped flowers over a long flowering season

  • Details 'Cooperi' is a compact evergreen shrub with lance-shaped leaves heavily marbled and blotched with white and sometimes tinged pink; flowers red

Characteristics

  • Foliage Evergreen

  • 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)

    H1B

Colour

Sunlight

  • Partial Shade

  • Aspect South-facing or West-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • MoistureWell-drained

  • SoilLoam

  • pHAlkaline, Neutral

Size

  • Ultimate height 1-1.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Under glass grow in a loam-based potting compost (JI No.2) in bright filtered light, providing moderate humidity and good ventilation. Water freely during the growing season and apply a balanced liquid fertiliser monthly. Water sparingly in winter

Propagation Propagate by seed at 13-18°C (55-64°F) in spring or propagate by semi-ripe cuttings in summer

Suggested planting locations and garden types Patio & Container Plants

How to care

Pruning Pruning group 9 little or no regular pruning evergreen shrubs

Pests Aphids, scale insects, mealybugs and glasshouse whitefly may be a problem when grown under glass

Diseases Powdery mildew may be a problem

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.