• 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

Verbascum bombyciferum

Broussa mullein

  • Other common names Broussa mullein

  • Synonyms Verbascum 'Broussa'

  • Family Scrophulariaceae

  • Genus Verbascum can be annuals, biennials, perennials or subshrubs mostly with hairy leaves and 5-petalled, saucer-shaped flowers

  • Details V. bombyciferum is a biennial, or short-lived, evergreen perennial covered with silky, silver hairs. The basal rosette of leaves may be up to 60cm across;  the sulphur yellow flowers, 4cm across, are sparsely borne on a densely woolly stem up to 1.8m tall, in summer

  • Plant range Asia Minor


  • Foliage Evergreen

  • Habit Columnar/Upright

  • 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

  • Exposure Exposed


  • Loam


  • Chalk


  • MoistureWell-drained

  • SoilLoam, Chalk

  • pHAlkaline


  • Ultimate height 1.5-2.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 1-2 years

How to grow

Cultivation Grow in poor, alkaline, well-drained soil in full sun. A drought-tolerant plant, it grows large and needs support in fertile soils

Propagation Propagate by seed sown in containers in a cold frame in spring or early summer, or by root cuttings in winter

Suggested planting locations and garden types Flower borders and beds Drought Resistant Cottage & Informal Garden Gravel Garden Wildlife Gardens

How to care

Pruning Remove faded flower spikes

Pests May be attacked by mullein moth caterpillars and figwort weevil

Diseases May be subject to powdery mildews

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