• 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

Alcea rosea 'Nigra'

hollyhock 'Nigra'

  • Other common names hollyhock 'Nigra'

  • Family Malvaceae

  • Genus Alcea are robust biennials or short-lived perennials with showy funnel-shaped flowers borne in tall, erect racemes in summer

  • Details 'Nigra' is a vigorous biennial or short-lived perennial, to 2m tall, with shallowly-lobed, rounded leaves and long erect racemes of single, open funnel-shaped, deep chocolate-maroon flowers

Characteristics

  • Foliage Deciduous

  • 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)

    H5

Colour

Sunlight

  • Full Sun

  • Aspect West-facing or South-facing

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Chalk

  • Loam

    Loam

  • Sand

    Sand

  • MoistureWell-drained

  • SoilChalk, Loam, Sand

  • pHAcid, Alkaline, Neutral

Size

  • 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 well-drained, moderately fertile soil in full sun. Stake (see staking perennials) on exposed sites

Propagation Propagate by seed sown in gentle heat in mid-winter or in-situ in spring

Suggested planting locations and garden types Wall-side Borders Flower borders and beds Coastal Cottage & Informal Garden

How to care

Pruning Cut back after flowering

Pests Young growth can be attacked by slugs and caterpillars; flea beetles occasionally causes significant defoliation

Diseases Susceptible to a hollyhock rust

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