• 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

Callitriche stagnalis

common water starwort

  • Other common names common water starwort

  • Synonyms Callitriche verna subsp. stagnalis

  • Family Plantaginaceae

  • Genus Callitriche can be terrestrial or aquatic perennials with slender stems bearing linear or spoon-shaped leaves and minute flowers in summer, useful oxygenating plants for ponds

  • Details C. stagnalis is an aquatic plant with spoon-shaped, bright green submerged leaves to 2cm long, and rosettes of broader floating leaves. Stems often root into wet mud to form a close mat; flowers insignificant

  • Plant range S Europe, N Afr.


  • Foliage Deciduous

  • Habit Mat 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)




  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered


  • Loam


  • MoisturePoorly-drained

  • SoilLoam

  • pHAcid, Alkaline, Neutral


  • Ultimate height Up to 10 cm

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1-2 years

How to grow

Cultivation Plant in ponds and streams at a depth of between 15cm-60cm (6in- 2ft)

Propagation Propagate by division or stem cuttings made in summer

Suggested planting locations and garden types Wildlife Gardens

How to care

Pruning Limit spread as necessary

Pests Generally pest free

Diseases Generally disease free

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