• 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

Physostegia virginiana 'Summer Snow'

obedient plant 'Summer Snow'

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
obedient plant 'Summer Snow'

© RHS 2002

  • Other common names obedient plant 'Summer Snow'

  • Synonyms Physostegia virginiana 'Snow Queen'

  • Family Lamiaceae

  • Genus Physostegia are erect rhizomatous herbaceous perennials with neatly arranged pairs of toothed leaves and terminal racemes of 2-lipped, tubular flowers in summer

  • Details 'Summer Snow' is a vigorous, erect perennial to 60cm in height, with sharply toothed, lance-shaped leaves and dense spikes of tubular white flowers 3cm in length

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)

    H7

Colour

Sunlight

  • Full Sun

  • Partial Shade

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

  • Exposure Exposed or Sheltered

Soil

  • Sand

    Sand

  • Loam

    Loam

  • Chalk

    Chalk

  • Clay

    Clay

  • MoistureMoist but well-drained

  • SoilSand, Loam, Chalk, Clay

  • pHAcid, Alkaline, Neutral

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 fertile, moist soil in full sun or partial shade

Propagation Propagate by division in winter or early spring before new growth starts

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

How to care

Pruning Cut back to the base in winter

Pests Generally pest free

Diseases May be subject to rots if rhizomes damaged

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