• 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

Primula japonica (Pf)

Japanese primrose

Japanese primrose

© RHS

  • Other common names Japanese primrose

  • Family Primulaceae

  • Genus Primula are herbaceous or semi-evergreen perennials, forming a basal rosette of simple leaves, with salver-shaped or bell-shaped flowers which may be solitary or carried in an umbel or in whorls on an erect stem

  • Horticultural Group Proliferae section primulas are moisture-loving herbaceous or semi-evergreen perennials forming a rosette of basal leaves, with erect stems each carrying several whorls of salver-shaped flowers

  • Details P. japonica is a deciduous perennial to 45cm tall, with a basal rosette of broad, crinkly light green leaves, and erect stems bearing several whorls of reddish-purple flowers in late spring and early summer

  • Plant range Japan

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)

    H6

Colour

Sunlight

  • Full Sun

  • Partial Shade

  • Aspect South-facing or North-facing or West-facing or East-facing

  • Exposure Sheltered

Soil

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilLoam

  • pHAcid, Neutral

Size

  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Grow in deep moist or moist but well-drained neutral to acid, humus-rich soil in full sun or partial shade

Propagation Propagate by seed. Sow on the surface of the compost as soon as ripe in late winter or early spring. Can be propagated by division between autumn and early spring. Take root cuttings when dormant in winter

Suggested planting locations and garden types Flower borders and beds Cottage & Informal Garden

How to care

Pruning Cut back after flowering

Pests May be attacked by aphids, vine weevil, slugs, leaf and bud eelworms and glasshouse red spider mite

Diseases May suffer from a virus, primula brown core and grey mould

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