• AGM plants

    AGM plants have been through a rigourous 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

Ceanothus 'Dark Star'

Californian lilac 'Dark Star'

AGM plants

AGM plants have been through a rigourous 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
Californian lilac 'Dark Star'

© � RHS 2003

  • Other common names Californian lilac 'Dark Star'

  • Genus Ceanothus can be evergreen or deciduous shrubs or small trees, with simple leaves and small blue, pink or white flowers in profuse axillary or terminal clusters. They are fast-growing but may be short-lived

  • Family Rhamnaceae / Rhamnaceae

  • Species 'Dark Star' is a spreading evergreen shrub with dark green, ovate leaves and clusters of deep blue-purple flowers on arching branches in late spring

Characteristics

  • Foliage Evergreen

  • 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)
    Old hardiness ratings

    While we update our systems with the new hardiness ratings you may still see old hardiness ratings in your search results. These are denoted as 'Old'.

    • H1 - Requires heated glass
    • H2 - Requires unheated glass
    • H3 - Hardy outside in some regions of the UK
    • H4 - Hardy throughout the UK
    • H1 + H3 - Requires heated glass but may be grown outside in summer

    For full details of the hardiness ratings see

    see more

    H4

Colour

Sunlight

  • Full Sun

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

  • Exposure Sheltered

Soil

  • Chalk

    Sand

  • Chalk

    Clay

  • Chalk

    Loam

  • MoistureWell-drained, Moist but well-drained

  • SoilSand, Clay, Loam

  • pHAlkaline, Neutral

Size

  • Ultimate height

    1.5-2.5 metres

  • Ultimate spread

    1.5-2.5 metres

  • Time to ultimate height

    5-10 years

How to grow

Cultivation Grow in well-drained soil sheltered from cold, drying winds

Propagation Propagate by semi-hardwood cuttings

Suggested planting locations and garden types Banks and Slopes Flower borders and beds Wall-side Borders City & Courtyard Gardens Cottage & Informal Garden Mediterranean Climate Plants

How to care

Pruning Pruning group 8

Pests Generally pest free

Diseases May be subject to honey fungus

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