• 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

Lobelia cardinalis

cardinal flower

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
  • Other common names cardinal flower
    bog sage

    hog's physic
    Indian pink
    red bay
    scarlet lobelia
    slinkweed
    water gladiole

    see more
  • Synonyms Lobelia fulgens
    Lobelia splendens

  • Family Campanulaceae

  • Genus Lobelia can be annuals, perennials or shrubs, with simple leaves and showy 2-lipped flowers that may be solitary or in racemes or panicles

  • Details L. cardinalis is an erect, clump-forming herbaceous perennial to 90cm in height, with rather glossy bright green oblong leaves and brilliant scarlet, two-lipped flowers 5cm in length in terminal spikes

  • Plant range N America

Characteristics

  • Foliage Deciduous

  • Habit Clump-forming

  • Toxicity Ingestion may cause severe discomfort

  • 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)

    H3

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Exposed or Sheltered

Soil

  • Loam

    Loam

  • MoisturePoorly-drained

  • SoilLoam

  • pHNeutral, Acid, Alkaline

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Grow in deep, fertile, reliably moist soil in full sun or partial shade

Propagation Propagate by seed sown in gentle heat as soon as ripe, or by bud cuttings in late summer

Suggested planting locations and garden types Flower borders and beds Cottage & Informal Garden

How to care

Pruning Cut back after flowering

Pests May be damaged by slugs and snails

Diseases A leaf spot may be a problem

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