Botanical profile

Buddleia 'Black Knight'

Latin name
Buddleia 'Black Knight'
Common name
Butterfly Bush 'Black Knight'
Type
Shrub
Family
Scrophulariaceae

Buddleia 'Black Knight', or "Black Knight" butterfly bush, is a vigorous and majestic ornamental shrub, known for its long spikes of very dark purple, almost black flowers, among the most intense of all buddleias. Its abundant, delicately fragrant summer blooms attract a wide variety of butterflies and pollinators, transforming the garden into a vibrant living scene. Its broad and supple habit, combined with grayish-green foliage, makes it an excellent choice for large beds, informal hedges, or background plantings. Being very floriferous on new wood, it responds well to spring pruning, which helps to control its size while encouraging spectacular blooming. 'Black Knight' brings depth, elegance, and intensity to summer landscapes.

Care guide

Growing conditions

Light, soil, water and hardiness

Hardiness zone
Hardiness Zones 5–9
Exposure
Sun
Watering
Moderate watering
Fertilization
Slow-release fertilizer 14-7-14 or 4-2-8. Fertilize monthly or as directed on the bag. Add Myke at planting.
Soil type
Neutral to slightly alkaline, well drained
Minimum temperature
'-28°C
Plant appearance

Blooming, foliage and shape

Blooming period
Summer
Flower color
Dark purple
Fruiting
Dry capsules with no decorative appeal
Foliage color
Green
Foliage type
Obsolete
Shape
Shrubby
Garden structure

Size and growth

Height
1.5 to 2 m (5 to 7 feet)
Width
1.5 m (5 feet)
Growth rate
fast
Not recommended for pets
Not recommended for pets

Pets

Pollinators
Attracts or supports pollinating insects

Pollinators

Butterflies
Plants that attract butterflies

Butterflies

Hummingbirds
Flowers that attract hummingbirds

Hummingbirds

The availability of our plants varies depending on arrivals, seasons, nursery production and supplier availability. Some varieties may be offered for a limited time only, depending on their natural cycle or current stock. These plant profiles are designed to guide and inspire you when choosing plants for the garden, landscaping projects, containers or long-lasting outdoor arrangements.