• 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 × speciosa 'Hadspen Purple' (PBR)

lobelia 'Hadspen Purple'

  • Other common names lobelia 'Hadspen Purple'

  • Synonyms Lobelia syphilitica 'Hadspen Purple'
    Lobelia × gerardii 'Hadspen Purple'

    Lobelia 'Hadspen Purple'
    Lobelia 'Hadspen Royal Purple'

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  • 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 'Hadspen Purple' is a semi-evergreen perennial, up to 60cm in height, with upright stems bearing ovate to lance-shaped, purple-flushed, light green leaves and terminal racemes of two-lipped, bright purple flowers from summer into autumn


  • Foliage Deciduous

  • Habit Columnar/Upright

  • 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)




  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered or Exposed


  • Sand


  • Loam


  • Clay


  • Chalk


  • MoistureMoist but well-drained

  • SoilSand, Loam, Clay, Chalk

  • pHAcid, Alkaline, Neutral


  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 2-5 years

How to grow

Cultivation Plant in deep, fertile, reliably moist soil in sun or partial shade. Feed every 2 weeks with a balanced liquid fertilizer until midsummer and a low nitrogen fertilizer for the remainder of the growing season. Protect the crown of the plant during winter with a thick, dry mulch

Propagation Divide large clumps of plants every second year in spring

Suggested planting locations and garden types Flower borders and beds Low Maintenance Wall-side Borders Garden Edging City & Courtyard Gardens Coastal Cottage & Informal Garden Wildlife Gardens

How to care

Pruning Cut down faded flower spikes in autumn

Pests Slugs may be a problem

Diseases May be subject to crown rot and a virus

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