• 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

Crocosmia × crocosmiiflora


  • Other common names montbretia

  • Synonyms Crocosmia 'Donegal'
    Montbretia × crocosmiiflora

  • Family Iridaceae

  • Genus Crocosmia are deciduous cormous perennials with erect, sword-shaped leaves and branched spikes of showy, funnel-shaped flowers in summer

  • Details C. × crocosmiiflora is a vigorous, variable hybrid, a cormous herbaceous perennial, typically up to 60cm high, with pale green leaves and slightly arching spikes of orange flowers, 3-5cm across, in summer


  • Foliage Deciduous

  • Habit Clump-forming

  • 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

  • Partial Shade

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

  • Exposure Exposed or Sheltered


  • Chalk


  • Clay


  • Loam


  • Sand


  • MoistureMoist but well-drained

  • SoilChalk, Clay, Loam, Sand

  • pHAcid, Alkaline, Neutral


  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation It is an invasive non-native plant in the United Kingdom, and since 2010 it has been listed in Schedule 9 of The Wildlife and Countryside Act 1981, so that under Section 14 it is illegal to plant or otherwise cause it to grow in the wild. In gardens, plant 8-10cm deep in spring, in fertile, retentive, humus-rich, moist but well-drained and preferably sandy soil in full sun or partial shade; if clumps become congested, divide them in early spring

Propagation Propagate by division of established clumps in spring, just before new growth starts

Suggested planting locations and garden types Cut Flowers Low Maintenance Banks and Slopes Flower borders and beds Wall-side Borders Coastal Cottage & Informal Garden Prairie Planting

How to care

Pruning No pruning required, except removal of dead leaves and flower stems before new growth starts in spring

Pests May be affected by glasshouse red spider mite

Diseases Generally disease free

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