• AGM plants

    AGM plants have been through a rigourous 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 maderense

Giant herb robert

AGM plants

AGM plants have been through a rigourous 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
Giant herb robert

© � Janet Cubey & Wolfgang Bopp 2000

  • Other common names Giant herb robert

  • 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

  • Family Geraniaceae / Geraniaceae

  • Species G. maderense is a robust but short-lived evergreen perennial or biennial to 1.5m, with attractively dissected leaves to 20cm in length and large panicles of purplish-pink flowers 4cm across, with darker centres

  • Plant range Madeira

Characteristics

  • Foliage Evergreen

  • Habit Tufted

  • 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)
    Old hardiness ratings

    While we update our systems with the new hardiness ratings you may still see old hardiness ratings in your search results. These are denoted as 'Old'.

    • H1 - Requires heated glass
    • H2 - Requires unheated glass
    • H3 - Hardy outside in some regions of the UK
    • H4 - Hardy throughout the UK
    • H1 + H3 - Requires heated glass but may be grown outside in summer

    For full details of the hardiness ratings see

    see more

    H3

Colour

Sunlight

  • Full Sun

  • Full Shade

  • Partial Shade

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

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Chalk

  • Chalk

    Clay

  • Chalk

    Sand

  • Chalk

    Loam

  • MoistureWell-drained

  • SoilChalk, Clay, Sand, Loam

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height

    1-1.5 metres

  • Ultimate spread

    0.5-1 metres

  • Time to ultimate height

    1-2 years

How to grow

Cultivation Grow outdoors in well-drained soil in either sun or shade in frost-free area. Grow under glass in loam-based compost with added sharp sand in bright filtered light. Remove flowered stems and old leaves to encourage the production of new leaves and flowers

Propagation Propagate by seed, division or take basal cuttings

Suggested planting locations and garden types Low Maintenance Cottage & Informal Garden Mediterranean Climate Plants

How to care

Pruning No pruning required

Pests Generally pest free

Diseases May be affected by a downy mildew and powdery mildews

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