• 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

Persicaria affinis 'Donald Lowndes'

Knotweed 'Donald Lowndes'

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
Knotweed 'Donald Lowndes'

© � RHS 2002

  • Other common names Knotweed 'Donald Lowndes'

  • Synonyms Polygonum affine 'Donald Lowndes'

  • Genus Persicaria can be annuals, herbaceous or evergreen perennials or sub-shrubs with simple leaves and small bell-shaped white or pink flowers in long-lasting spikes or panicles

  • Family Polygonaceae / Polygonaceae

  • Species 'Donald Lowndes' is a mat-forming, partially evergreen perennial to 20cm in height, with dark green, narrowly elliptic leaves and erect spikes of small pink flowers which darken with age, finally turning orange-brown

Characteristics

  • Foliage Semi-evergreen

  • 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)
    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

    H5

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Exposed or Sheltered

Soil

  • Chalk

    Clay

  • Chalk

    Loam

  • Chalk

    Sand

  • Chalk

    Chalk

  • MoistureMoist but well-drained

  • SoilClay, Loam, Sand, Chalk

  • pHAlkaline, Neutral, Acid

Size

  • Ultimate height

    0.1-0.5 metres

  • Ultimate spread

    0.1-0.5 metres

  • Time to ultimate height

    5-10 years

How to grow

Cultivation Easy to grow in any moist soil in full sun or partial shade

Propagation Propagate by division in spring or autumn

Suggested planting locations and garden types Banks and Slopes Flower borders and beds Garden Edging Ground Cover City & Courtyard Gardens Coastal Cottage & Informal Garden Gravel Garden Patio & Container Plants Rock Garden

How to care

Pruning Deadhead faded spikes

Pests Generally pest free

Diseases Generally disease free

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