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Buddleja davidii 'Black Knight'
  • RHS AGM
  • RHS Plants for pollinators

butterfly bush 'Black Knight'

A vigorous large deciduous shrub to 3m, with somewhat arching growth and lance-shaped leaves, whitish beneath. Flowers scented, deep purple, in elongated panicles at tips of current year's growth

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Size
Ultimate height
2.5–4 metres
Time to ultimate height
5–10 years
Ultimate spread
2.5–4 metres
Growing conditions
Chalk
Clay
Loam
Sand
Moisture
Moist but well–drained, Well–drained
pH
Acid, Alkaline, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Green White
Summer Purple Green White
Autumn Purple Green White
Winter
Position
  • Full sun
  • Partial shade
Aspect

South–facing or East–facing or West–facing

Exposure
Exposed or Sheltered
Drought resistance
Yes
Hardiness
H6
Botanical details
Family
Scrophulariaceae
Native to GB / Ireland
No
Foliage
Deciduous
Habit
Bushy
Genus

Buddleja can be evergreen or deciduous shrubs, occasionally trees or scrambling climbers with simple leaves and panicles of small, tubular fragrant flowers

Name status

Accepted

How to grow

Cultivation

Buddleja perform best when grown in a sunny, well-drained situation. See buddleja cultivation for more detailed advice

Propagation

Propagate by semi-hardwood cuttings

Suggested planting locations and garden types
  • Cottage and informal garden
  • Wildlife gardens
  • Low Maintenance
  • Flower borders and beds
Pruning

Pruning group 6

Pests

May be susceptible to aphids, capsid bugs, caterpillars, earwigs, figwort weevils, glasshouse red spider mite, leaf and bud eelworm, and mullein moth

Diseases

May be susceptible to honey fungus, fungal leaf spot, and virus diseases

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