• 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

Betonica macrantha

big betony

  • Other common names big betony

  • Synonyms Stachys grandiflora
    Stachys spicata

    Stachys macrantha
    Betonica grandiflora

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  • Family Lamiaceae

  • Genus Betonica is a genus of native perennial wildflowers with narrow, oval leaves on upright stems. Bright purple to red flowers appear throughout the summer and into early autumn.

  • Details S. macrantha is an upright perennial to 60cm tall, with neatly toothed, oblong leaves and hooded pinky-purple flowers, 3.5cm long, in dense spikes in summer and early autumn

Characteristics

  • Foliage Deciduous

  • Habit Bushy

  • 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)

    H7

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Sheltered

Soil

  • Chalk

    Chalk

  • Loam

    Loam

  • Sand

    Sand

  • MoistureWell-drained, Moist but well-drained

  • SoilChalk, Loam, Sand

  • pHAlkaline, Neutral, Acid

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 moderately fertile, well-drained soil in full sun or partial shade

Propagation Divide in spring. Propagate by seed in spring or autumn and keep in a cold frame

Suggested planting locations and garden types Flower borders and beds Underplanting of Roses and Shrubs City & Courtyard Gardens Coastal Cottage & Informal Garden Wildlife Gardens

How to care

Pruning Remove flowered stems

Pests Slugs and snails may be a problem

Diseases May be affected by powdery mildews

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