Black Knight Butterfly Bush

The Darkest, Most Dramatic Butterfly Bush Available

Black Knight Butterfly Bush (Buddleia davidii 'Black Knight') produces some of the deepest, richest purple flower spikes of any butterfly bush — a near-black violet that is dramatically darker than most other varieties. Its long, arching flower wands open from midsummer through fall, releasing a sweet honey fragrance that draws butterflies, hummingbirds, and bees from remarkable distances. It’s one of the fastest-growing flowering shrubs available, capable of reaching 6–10 ft in a single season, and it blooms most prolifically in full sun with minimal care. Deadhead spent flower spikes regularly to extend the bloom season and encourage continuous new flower production.

Why Black Knight Stands Out

• Deepest purple of any butterfly bush — near-black violet flower spikes; dramatically darker than standard purple varieties; a true focal point in any landscape
• Exceptional butterfly and pollinator attraction — one of the most effective butterfly-attracting plants available; also draws hummingbirds and bees in large numbers
• Sweet honey fragrance — long flower spikes carry a rich, sweet scent that perfumes the surrounding garden
• Extremely fast growth — can reach 6–10 ft in a single growing season; provides immediate landscape impact
• Drought-tolerant once established — highly resilient in dry conditions; one of the most heat and drought-tolerant flowering shrubs available
• Reblooms with deadheading — removing spent flower spikes promptly encourages continuous new blooms from midsummer through frost
• Excellent cut flower — long flower spikes are stunning in fresh arrangements

Hardiness & Growing Zones

• USDA Hardiness Zones: 5–9
• Zones 5–6: May die back to the ground in severe winters but regrows vigorously from the roots in spring; blooms on new wood so late-season dieback does not affect flowering; treat as a perennial in these zones
• Zones 7–8: Ideal conditions; vigorous growth with prolific, continuous blooming from midsummer through fall
• Zone 9: Thrives in heat; may bloom earlier (late spring) and continue longer into fall; provide consistent moisture during the hottest periods
• Sunlight: Full sun (6–8+ hours required; more sun = more blooms)
• Soil: Adaptable to most well-drained soils; tolerates poor, rocky, and sandy conditions; avoid waterlogged sites
• Mature size: 6–10 ft tall × 4–6 ft wide (in warm zones); 3–5 ft in zones 5–6 where it dies back annually
• Bloom time: Midsummer through fall (July–October in most zones)

Planting & Care Tips

Plant in the sunniest spot available with well-drained soil. Water during the first growing season to establish roots; once established, butterfly bush is quite drought-tolerant. Fertilize lightly in early spring with a balanced slow-release fertilizer. Deadhead spent flower spikes by cutting them back to the next set of leaves — this is the single most important maintenance task, as it extends the bloom season significantly and prevents self-seeding. In late winter or early spring, cut the entire plant back hard (to 12–18 inches) to encourage vigorous new growth and the best flower production. Note: Buddleia davidii is considered invasive in some regions; check local regulations and deadhead diligently to prevent seed spread.

Available Sizes

• 1–2 ft. (3 Gallon) — well-rooted young shrub; will reach full size by end of first growing season
• 3 Gallon — established root system; great value; same rapid growth potential