Species

Buddleja davidiiButterfly Bush

58 other cultivars

shrub RHS Award

Black Knight Butterfly Bush

Buddleja davidii 'Black Knight'

$14.95

The Story

Plant Bio

A fast-growing shrub known for its fragrant purple flowers and ability to attract butterflies.

Black Knight is distinguished by its dark purple flowers that can appear almost black, and its strong upright growth habit.

Uses & Benefits:

Buddleja davidii 'Black Knight' offers striking dark foliage and vibrant purple flowers, perfect for attracting pollinators and creating visual interest.

Provides a tall, fast-growing privacy screen and reduces garden maintenance with its low fuss nature.

Attracts butterflies, bees, and hummingbirds, supporting local biodiversity.

SpeciesBuddleja davidiiButterfly Bush

Essentials

At a Glance

Plant Type

Shrub

Height

84 inches

Width

84 inches

Light

Full Sun

Zones

5, 6, 7, 8, 9, 10

Water

Moderate, drought tolerant once established

Humidity

Prefers moderate humidity

Lifespan

10+ years

Native To

China

Toxicity

Non-toxic to humans and pets

Bloom period

Late summer – Early fall

In flower about 2 months of the year

Marketplace

Where to Buy

PlantingTree

In Stock$14.95

Fast Growing Trees

In Stock$21.95

Spring Hill Nursery

Bareroot

In Stock$29.99

Nature Hills

In Stock$40.75

Shipping costs Year-round shipping Free shipping

Planting

How to Grow

Tuck seeds into well-draining soil in early spring for best germination.
Mist cuttings regularly to maintain humidity and encourage root growth.
Transplant young plants in spring after the last frost for optimal establishment.
Prune back in late winter to promote bushy growth and flowering.
Apply slow-release fertilizer in early spring to support vigorous growth.
Water deeply during dry spells to keep soil moist but not waterlogged.

Pro Tip

Use well-draining soil and full sun for vibrant blooms and healthy growth.

Keep It Thriving

Care Guide

Do

Provide full sun to ensure abundant flowering 🌞
Water regularly, especially during dry periods 💧
Prune in late winter to shape and encourage new growth
Apply balanced fertilizer in spring for best results
Mulch around base to retain moisture and suppress weeds

Don't

Avoid overwatering to prevent root rot ❌
Don’t prune in late summer as it may reduce flowering ❌
Never neglect pest monitoring, early detection is key ❌
Avoid planting in poorly drained soil to prevent disease ❌
Don’t fertilize excessively, too much can harm the plant ❌

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Deadhead
Fertilize
Plant
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Vivid garden border with dark foliage contrastFragrant shrub for wildlife attracting pollinatorsTall, colorful screen for privacy in garden

Companion Plants

Lavender Salvia Echinacea Coreopsis Rudbeckia

Multiply

Propagation Methods

Good to Know

Common Questions

Black Knight Butterfly Bush questions

What zones can Black Knight Butterfly Bush grow in?

Black Knight Butterfly Bush is hardy in USDA Zones 5–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Black Knight Butterfly Bush deer resistant?

Yes — Black Knight Butterfly Bush is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Black Knight Butterfly Bush bloom?

Black Knight Butterfly Bush typically blooms in late summer through early fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Black Knight Butterfly Bush need full sun?

Black Knight Butterfly Bush does best in full sun (6+ hours).

Is Black Knight Butterfly Bush drought tolerant?

Yes — once established (usually after the first full season), Black Knight Butterfly Bush handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.