• 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

Iris unguicularis

Algerian iris

Algerian iris

© RHS 2003

  • Other common names Algerian iris
    Algerian winter iris

    winter iris

    see more
  • Synonyms Iris stylosa

  • Family Iridaceae

  • Genus Iris may be rhizomatous or bulbous perennials, with narrow leaves and erect stems bearing flowers with 3 large spreading or pendent fall petals, alternating with 3 erect, often smaller, standard petals, in late winter, spring or early summer

  • Details I. unguicularis is a vigorous evergreen rhizomatous perennial to 30cm in height, with copious dark green leaves and very fragrant, deep violet flowers 5-8cm in width, the falls marked with white and deep yellow at the base, in late winter

  • Plant range N Africa to SW Asia


  • Foliage Evergreen

  • Habit Clump-forming

  • Fragrance Flower

  • Toxicity Ingestion may cause severe discomfort

  • 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

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

  • Exposure Exposed or Sheltered


  • Chalk


  • Chalk


  • Chalk


  • Chalk


  • MoistureWell-drained

  • SoilClay, Loam, Sand, Chalk

  • pHAlkaline, Neutral


  • 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 well-drained or sharply drained neutral or slightly alkaline soil. Ideal at the base of a sunny wall

Propagation Propagate by division from midsummer to early autumn, plant immediately in flowering positions

Suggested planting locations and garden types Banks and Slopes Flower borders and beds Cut Flowers Wall-side Borders City & Courtyard Gardens Coastal Cottage & Informal Garden Patio & Container Plants

How to care

Pruning Cut back after flowering

Pests Slugs and snails may be a problem

Diseases May be subject to bacterial soft rot, grey moulds and a virus

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