• 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

Vinca difformis

intermediate periwinkle

  • Other common names intermediate periwinkle

  • Family Apocynaceae

  • Genus Vinca can be evergreen subshrubs or herbaceous perennials, with simple, paired leaves and solitary, 5-lobed, salver-shaped flowers in the leaf axils

  • Details V. difformis is a vigorous, prostrate evergreen sub-shrub with rooting stems bearing ovate, evergreen leaves, and short upright leafy stems with pale whitish-blue flowers 4cm across, in late winter and early spring

  • Plant range N Africa & SW Europe


  • Foliage Evergreen

  • Habit Mat forming

  • Toxicity

  • 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)




  • Full Sun

  • Full Shade

  • Partial Shade

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

  • Exposure Sheltered or Exposed


  • Chalk


  • Chalk


  • Chalk


  • Chalk


  • MoistureWell-drained, Moist but well-drained, Poorly-drained

  • SoilChalk, Clay, Sand, Loam

  • pHAcid, Alkaline, Neutral


  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 1-1.5 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Easy to grow in all but the driest soils. Flowers best in full sun but very useful for shady areas. Can be invasive

Propagation Propagate by division in spring or autumn and by semi-hardwood cuttings in summer

Suggested planting locations and garden types Ground Cover Rock Garden

How to care

Pruning Pruning group 6

Pests Can get aphids

Diseases May be subject to a rust

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