• 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 sieboldii (Co)

Siebold primrose

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 Siebold primrose

  • Synonyms Primula saxatilis

  • 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 Cortusoides section primulas are woodland perennials with long-stalked, rounded, lobed and hairy leaves, and usually rosy-pink flowers in a single umbel

  • Details P. sieboldii is a perennial to 30cm, with rosettes of broadly oblong to ovate, pale green, softly downy leaves and erect stems bearing umbels of purple to crimson, pink or white flowers 2.5-4cm wide in late spring and early summer

  • Plant range E Siberia to 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)

    H5

Colour

Sunlight

  • Partial Shade

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

  • Exposure Sheltered

Soil

  • Clay

    Clay

  • Loam

    Loam

  • MoistureMoist but well-drained

  • SoilClay, Loam

  • pHAcid, 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 in partial shade, in deep humus-rich, moist, neutral to acid loam soil; tolerates full sun if the soil remains moist at all times

Propagation Propagate by division as it comes into growth or propagate by seed

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

How to care

Pruning Tidy plant after flowering and remove diseased or damaged leaves

Pests Prone to aphids, leafhoppers, vine weevil and slugs

Diseases May be affected by a virus, grey mould (botrytis) or primula brown core

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