• 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 psilostemon

Armenian cranesbill

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
  • Other common names Armenian cranesbill

  • Synonyms Geranium armenum

  • 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. psilostemon is an herbaceous perennial forming a large clump of lobed leaves, tinted red in autumn. Flowers 4cm in width, magenta-crimson with black centres, on upright stems to 1.2m

  • Plant range NE Turkey

Characteristics

  • Foliage Deciduous

  • Habit Clump-forming

  • 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

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

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Chalk

  • Chalk

    Loam

  • Chalk

    Sand

  • Chalk

    Clay

  • MoistureMoist but well-drained, Well-drained

  • SoilChalk, Loam, Sand, Clay

  • 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 any, moderately fertile soil apart from waterlogged soils. Full sun or partial shade is best but shade is tolerated. Quite a tall species so may need support to prevent it flopping

Propagation Propagate by division in spring or propagate by basal cuttings in early to mid spring and root with bottom heat

Suggested planting locations and garden types Banks and Slopes Flower borders and beds Ground Cover Low Maintenance Underplanting of Roses and Shrubs City & Courtyard Gardens Cottage & Informal Garden Patio & Container Plants Wildlife Gardens

How to care

Pruning Remove flowered stems and old leaves to encourage the production of fresh leaves and flowers

Pests May be attacked by vine weevil, sawflies, slugs and snails

Diseases May be subject to powdery mildews, a downy mildew and a virus

Advertise here

Did you find the information you were looking for?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now