• 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

Allium 'Purple Giant'

allium 'Purple Giant'

  • Other common names allium 'Purple Giant'

  • Family Alliaceae

  • Genus Allium are bulbous herbaceous perennials with a strong onion or garlic scent, linear, strap-shaped or cylindrical basal leaves and star-shaped or bell-shaped flowers in an umbel on a leafless stem

  • Details 'Purple Giant' is a bulbous herbaceous perennial, up to about 75cm high, with linear green leaves which start to die down when the dense, spherical umbels, about 25-30cm across, of purplish-pink flowers appear in summer

Characteristics

  • Foliage Deciduous

  • Habit Columnar/Upright

  • 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)

    H5

Colour

Sunlight

  • Full Sun

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

  • Exposure Sheltered

Soil

  • Chalk

    Chalk

  • Loam

    Loam

  • Sand

    Sand

  • MoistureMoist but well-drained, Well-drained

  • SoilChalk, Loam, Sand

  • pHAcid, Alkaline, Neutral

Size

  • Ultimate height 0.5-1 metres

  • Ultimate spread 0.1-0.5 metres

  • Time to ultimate height 1-2 years

How to grow

Cultivation Grow in full sun in a sheltered position in well-drained soil; for more advice see Allium cultivation

Propagation Propagate by offsets: once flowering is over and the leaves have died down, lift the bulbs, detach the offsets, plant larger ones where you want them to grow, and grow smaller ones in gritty compost before planting out; for more advice see bulb propagation

Suggested planting locations and garden types Cut Flowers Flower borders and beds Drought Resistant Low Maintenance City & Courtyard Gardens Gravel Garden Patio & Container Plants Cottage & Informal Garden

How to care

Pruning No pruning required

Pests May be affected by onion fly, allium leaf mining fly, slugs and snails

Diseases May be affected by onion white rot and a downy mildew

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