• 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

Streptocarpus 'Polka-dot Purple'

Cape primrose 'Polka-Dot Purple'

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
Cape primrose 'Polka-Dot Purple'

© RHS

  • Other common names Cape primrose 'Polka-Dot Purple'

  • Family Gesneriaceae

  • Genus Streptocarpus can be annuals, perennials or subshrubs, with usually wrinkled, lance-shaped to rounded leaves and clusters of tubular to trumpet-shaped flowers with 5 spreading lobes, often borne throughout the year

  • Details 'Polka-Dot Purple' is a tender perennial plant with linear, hairy, wrinkled mid-green leaves. Tubular purple flowers with spreading lobes have white edging and speckling and are borne in profusion over a long period

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)

    H1C

Colour

Sunlight

  • Partial Shade

  • Aspect West-facing or East-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilLoam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1-2 years

How to grow

Cultivation Grow as a houseplant in loamless potting compost on an east or west windowsill, or grow in a temperate or warm greenhouse in bright filtered light with shade from hot sun. Water sparingly as compost dries in winter and in the growing season water freely allowing compost to dry out between waterings; feed fortnightly with a high-potassium fertiliser

Propagation Propagate by division or take leaf cuttings in spring or early summer. Root stem-tip 5-8cm long in spring with bottom heat

Suggested planting locations and garden types Patio & Container Plants

How to care

Pruning No pruning necessary

Pests Glasshouse leafhoppers, mealybugs, thrips, tarsonemid mites and vine weevil larvae may be a problem

Diseases Generally disease free but prone to basal rot if overwatered and grey moulds

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