• 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

Pontederia cordata

pickerel weed

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 pickerel weed
    heart-leaved pickerel weed

    wampee

    see more
  • Family Pontederiaceae

  • Genus Pontederia are herbaceous perennials from marginal aquatic habitats, forming clumps of erect, linear or lance-shaped leaves, with 2-lipped blue flowers in dense terminal spikes in late summer and early autumn

  • Details P. cordata is a marginal aquatic perennial to 1.2m, forming a clump of erect, lance-shaped or ovate, bright green leaves to 18cm in length, with dense erect spikes, to 15cm in length, of small tubular deep blue flowers in late summer

  • Plant range Eastern N America to Caribbean

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)

    H5

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Clay

    Clay

  • Loam

    Loam

  • MoisturePoorly-drained

  • SoilClay, Loam

  • pHNeutral, Acid, Alkaline

Size

  • Ultimate height 1-1.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Grow in baskets of fertile loam, in shallow water and in full sun

Propagation Propagate by division in spring as growth starts or propagate by seed sown in containers as soon as ripe

Suggested planting locations and garden types Low Maintenance

How to care

Pruning Cut back after flowering

Pests Generally pest free

Diseases Generally disease free

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