• 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

Kniphofia northiae

giant red-hot poker

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
giant red-hot poker

© RHS

  • Other common names giant red-hot poker

  • Synonyms Tritoma northiae

  • Family Asphodelaceae

  • Genus Kniphofia may be evergreen or herbaceous perennials, with linear or strap-shaped leaves and erect stems bearing a dense raceme of tubular, usually pendent flowers

  • Details K. northiae is an evergreen perennial producing a rosette of broad, smooth, strap-shaped leaves. The flowers have densely-packed florets opening a reddish-orange, fading through yellow to greenish-cream

  • Plant range South Africa

Characteristics

  • Foliage Evergreen

  • Habit Tufted

  • 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)

    H4

Colour

Sunlight

  • Full Sun

  • Aspect South-facing or West-facing

  • Exposure Exposed or Sheltered

Soil

  • Loam

    Loam

  • Sand

    Sand

  • MoistureMoist but well-drained

  • SoilLoam, Sand

  • pHAcid, Neutral, Alkaline

Size

  • Ultimate height 1-1.5 metres

  • Ultimate spread 0.5-1 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Best grown in full sun in a sandy soil that has been enriched with humus, but any deep, moist but well-drained soil will do

Propagation Propagate by seed sown in containers in a cold frame in spring, or by division

Suggested planting locations and garden types Flower borders and beds Coastal Gravel Garden Architectural

How to care

Pruning Old flower stems can be cut down after flowering

Pests Can be damaged by slugs and snails

Diseases Generally disease free

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