• 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

Thalictrum aquilegiifolium 'Thundercloud'

French meadow rue 'Thundercloud'

French meadow rue 'Thundercloud'

© RHS 1999

  • Other common names French meadow rue 'Thundercloud'

  • Synonyms Thalictrum aquilegiifolium PURPLE CLOUD
    Thalictrum aquilegiifolium 'Purple Cloud'

    Thalictrum delavayi 'Thundercloud'

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  • Family Ranunculaceae

  • Genus Thalictrum can be rhizomatous or tuberous perennials with ternately or pinnately divided, often attractive foliage, and panicles or racemes of small flowers with showy stamens and sometimes large colourful petal-like sepals

  • Details 'Thundercloud' is an erect herbaceous perennial to 90cm in height, with mid-green leaves composed of small, obovate leaflets, and branched stems bearing large fluffy heads of small flowers with prominent deep rose-purple stamens in early summer


  • Foliage Deciduous

  • Habit Clump-forming

  • Toxicity Contact with foliage may irritate the skin

  • 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)




  • Partial Shade

  • Aspect East-facing

  • Exposure Sheltered


  • Chalk


  • Loam


  • Clay


  • MoistureMoist but well-drained, Poorly-drained

  • SoilChalk, Loam, Clay

  • 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 Grow in moist, humus-rich soil in partial shade

Propagation Propagate by seed in pots in a cold frame as soon as seed is ripe or in early spring. Propagate by division in spring as new growth begins

Suggested planting locations and garden types Flower borders and beds Low Maintenance Underplanting of Roses and Shrubs City & Courtyard Gardens Cottage & Informal Garden Prairie Planting Wildflower meadow

How to care

Pruning Cut down stems once flowering is over

Pests Slugs may be a problem

Diseases May be subject to powdery mildews in dry conditions

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