• 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

Galium odoratum

sweet woodruff

sweet woodruff

© RHS 2002

  • Other common names sweet woodruff
    hay plant

    sweet grass

    see more
  • Synonyms Asperula odorata

  • Family Rubiaceae

  • Genus Galium can be annuals or perennials, with weak, sometimes scrambling stems bearing whorls of narrow leaves and usually terminal panicles of small, white or yellow flowers

  • Details G. odoratum is a vigorous rhizomatous perennial forming a wide mat of erect stems to 30cm, bearing whorls of bright green, lance-shaped leaves, hay-scented when dry, with terminal clusters of small white, starry flowers from late spring

  • Plant range Europe, N Africa


  • 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)




  • Partial Shade

  • Aspect North-facing or East-facing

  • Exposure Sheltered


  • Chalk


  • Chalk


  • Chalk


  • Chalk


  • MoistureMoist but well-drained

  • SoilChalk, Clay, Sand, Loam

  • pHAcid, Alkaline, Neutral


  • Ultimate height

    0.1-0.5 metres

  • Ultimate spread

    1-1.5 metres

  • Time to ultimate height

    5-10 years

How to grow

Cultivation Grow in any moist but well-drained soil in partial shade, strong sun will scorch the leaves. Can be invasive

Propagation Propagate by seed or division of rhizomes in autumn or early spring

Suggested planting locations and garden types Flower borders and beds Ground Cover Underplanting of Roses and Shrubs Cottage & Informal Garden Wildlife Gardens

How to care

Pruning No pruning required

Pests Generally pest free

Diseases Generally disease free

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