• 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

Geranium phaeum

black widow

  • Other common names black widow
    dusky cranesbill

    dusky-flowered cranesbill
    mourning widow

    see more
  • Family Geraniaceae

  • Genus Geranium can be annuals, biennials and perennials, herbaceous or evergreen, with rounded, usually palmately lobed or divided leaves, and lax inflorescences of rounded, 5-petalled flowers

  • Details G. phaeum is a erect, clump-forming perennial with lobed leaves often with brownish markings, and flat, outward-facing dusky purple, lilac or white flowers 2cm wide in late spring and early summer

  • Plant range S C & W Europe

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • 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)

    H7

Colour

Sunlight

  • Full Sun

  • Partial Shade

  • Full Shade

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

  • Exposure Sheltered

Soil

  • Sand

    Sand

  • Clay

    Clay

  • Chalk

    Chalk

  • Loam

    Loam

  • MoistureWell-drained

  • SoilSand, Clay, Chalk, Loam

  • pHAcid, Alkaline, Neutral

Size

  • 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 moderatly fertile, well-drained soil in sun or part shade but most soils (unless waterlogged) are tolerated. Especially good in damp shade

Propagation Propagate by division in spring or basal cuttings in early or mid-spring and root with bottom heat. Propagate by seed in containers outdoors as soon as ripe or in spring

Suggested planting locations and garden types Flower borders and beds Underplanting of Roses and Shrubs Cottage & Informal Garden

How to care

Pruning Cut flowered stems and old leaves to the base to encourage new foliage and flowers

Pests May be damaged by capsid bug, vine weevil larvae, sawfly larvae, slugs and snails

Diseases A virus or downy mildew may be troublesome. Powdery mildew may be a problem in dry conditions

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