Black Knight Butterfly Bush

Deep Purple Blooms
Fragrant Summer Flowers
Pollinator Garden Favorite

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Black Knight Butterfly Bush

Sunlight
Can grow in a range from full sun to partial shade. They need at least six hours of direct, unfiltered sunlight per day.
Watering
Regular watering schedule for the first six months. Once established, rainwater should be sufficient.
Fertilizing
Should not need any extra fertilizer unless your entire lawn and garden have problems and needs regular fertilizing.

Black Knight Butterfly Bush

Black Knight Butterfly Bush is a vigorous deciduous flowering shrub known for long, fragrant, deep purple flower panicles and graceful arching stems. This classic butterfly bush brings bold summer color, pollinator appeal, and vertical texture to sunny borders, cottage gardens, mixed shrub beds, and informal screens.

Why choose Black Knight Butterfly Bush?

Choose Black Knight Butterfly Bush for dramatic color and a lively summer garden display. Its dark purple blooms are among the richest shades in traditional butterfly bush selections, standing out beautifully against gray-green foliage. The flowers provide nectar for butterflies, bees, and hummingbirds, while the fast-growing, arching habit helps fill sunny spaces quickly. It is especially useful where gardeners want a showy, fragrant flowering shrub with a relaxed, natural look.

Key Characteristics

Botanical Name: Buddleja davidii ‘Black Knight’
Common Name: Black Knight Butterfly Bush
Plant Type: Deciduous flowering shrub
Growth Habit: Upright, arching, multi-stemmed shrub

Black Knight Butterfly Bush Additional Information

Black Knight Butterfly Bush produces elongated clusters of deep violet-purple, fragrant flowers in summer, often continuing into fall with regular removal of spent blooms. The narrow gray-green leaves and long arching stems give the plant a loose, fountain-like form that works well at the back of perennial borders, in butterfly gardens, along fences, or as a colorful seasonal screen. In colder climates, stems may die back substantially in winter and regrow strongly from the base in spring.

This shrub blooms on new wood, so late-winter or early-spring pruning helps encourage fresh growth and strong flowering stems. Mature size varies by climate and pruning, but it often reaches about 6–8 feet tall and 4–6 feet wide in favorable conditions. Because Buddleja davidii can reseed in some regions, removing spent flower panicles before seed develops is a practical way to keep plantings tidy and managed.

Planting & Care

1. Planting: Plant Black Knight Butterfly Bush in full sun with well-drained soil. Set the root ball level with the surrounding soil, backfill firmly, and water thoroughly to settle the roots.

2. Watering: Water consistently during the first growing season while the root system develops. Once established, provide deep watering during extended dry periods, allowing the soil to drain well between waterings.

3. Pruning: Prune in late winter or early spring before new growth begins. Cutting back older stems encourages vigorous new shoots and supports larger summer flower panicles.

4. Mulching: Apply a 2–3 inch layer of mulch around the root zone to conserve moisture and moderate soil temperature. Keep mulch slightly away from the crown and main stems.

Related Resources

FAQs

How big does Black Knight Butterfly Bush get?
Black Knight Butterfly Bush commonly grows about 6–8 feet tall and 4–6 feet wide, though size can vary with winter conditions, climate, and annual pruning.
When does Black Knight Butterfly Bush bloom?
It blooms in summer and can continue into fall. Removing faded flower clusters helps keep the plant attractive and may encourage additional blooms.
Does Black Knight Butterfly Bush need full sun?
Yes. Full sun is best for strong flowering, sturdy growth, and rich purple bloom color. Aim for at least six hours of direct sunlight per day.

Shipping Details

Estimated Shipping Time: Most orders ship immediately. As noted on the website, some items are seasonal, and may only ship in spring or fall. Once your order is shipped, you’ll receive an email with a tracking number.

Amount of Order	Shipping Charge
Local Delivery	FREE SHIPPING
Non-Local Delivery	Varies based on UPS shipping

Thrives
Full Sun
Flowering

Mature Height	Extra Large: Above 6 ft
Mature Spread	0-5 ft
Growth Rate	Fast, Moderate
Botanical Name	Buddleja davidii 'Black Knight'
Bloom Time	Early Summer, Late Summer
Deer Resistant	Usually
Family	Scrophulariaceae
Flower Color	Blue/Purple
Hardiness Zones	5, 6, 7, 8, 9
Light Needs	Full Sun, Partial Sun
Maintenance	Low
Size	#3 Container, #7 Container

Map of the United States with most states filled in dark green and a few states left uncolored in white, indicating coverage in the shaded areas.

Growing Zones 5-9 Outdoors

(Hardy down to -20)

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Family	Hydrangeaceae	Hydrangeaceae	Rosaceae	Rosaceae	Adoxaceae	Oleaceae
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