• 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

Symphytum ibericum

Iberian comfrey

Iberian comfrey

© RHS 2003

  • Other common names Iberian comfrey

  • Family Boraginaceae

  • Genus Symphytum are rhizomatous herbaceous perennials, sometimes invasive, with large leaves and nodding clusters of tubular flowers

  • Details S. ibericum is a perennial to 40cm in height, with ovate leaves and pale yellow flowers opening from red buds in late spring

  • Plant range Cauc. & NE Turkey

Characteristics

  • Foliage Deciduous

  • Habit Spreading / Branched

  • 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)

    H6

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Exposed or Sheltered

Soil

  • Clay

    Clay

  • Loam

    Loam

  • Chalk

    Chalk

  • Sand

    Sand

  • MoistureMoist but well-drained, Poorly-drained

  • SoilClay, Loam, Chalk, Sand

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.1-0.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Grow in moderately fertile, moist soil in full sun or partial shade. Can be invasive so site with care

Propagation Propagate by division of fleshy roots in spring. Propagate by root cuttings in early winter. Propagate by seed sown in pots in a cold frame in autumn or spring

Suggested planting locations and garden types Flower borders and beds Ground Cover Banks and Slopes Cottage & Informal Garden Wildlife Gardens

How to care

Pruning Cut back after flowering to encourage neat, young foliage

Pests Generally pest free

Diseases Generally disease free

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