• 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

Potamogeton crispus

curled pondweed

  • Other common names curled pondweed
    curly pondweed

    water calthrops

    see more
  • Family Potamogetonaceae

  • Genus Potamogeton can be marginal or deep water aquatic perennials, with translucent submerged and leathery floating leaves, and small spikes of inconspicuous flowers held below or just above water level

  • Details P. crispus is a perennial with narrowly lance-shaped or oblong submerged leaves with strongly undulate margins when mature, but no floating leaves, and insignificant reddish flowers in summer


  • Foliage Deciduous

  • Habit Submerged

  • 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)




  • Full Sun

  • Partial Shade

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

  • Exposure Exposed or Sheltered


  • Sand


  • Loam


  • MoisturePoorly-drained

  • SoilSand, Loam

  • pHNeutral, Acid, Alkaline


  • Ultimate height Up to 10 cm

  • Ultimate spread 1-1.5 metres

  • Time to ultimate height 5-10 years

How to grow

Cultivation Grow in baskets of sandy loam in the bottom mud of the pond, in full sun or partial shade

Propagation Propagate by stem cuttings from mid spring to early summer

Suggested planting locations and garden types Low Maintenance

How to care

Pruning Thin on a regular basis to keep in check

Pests Generally pest free

Diseases Generally disease free

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