Black Knight Butterfly Bush (Buddleja davidii 'Black Knight')

Black Knight Butterfly Bush (Buddleja davidii 'Black Knight') is a well-branched shrub with a spreading, arching habit and willowy gray-green leaves. Large, fragrant, spike-like clusters of deep purple, nearly black flowers bloom in summer and attract butterflies.

Removing spent flowers can encourage continued flowering into fall. Grow in full sun and well-drained soil.

Growing details

• Plant type: Shrub
• Species origin: China
• Mature height: 6–8 feet if not cut back
• Mature spread: 3–5 feet
• Spacing: Approximately 4 feet apart
• Hardiness: USDA zones 5–9
• Light: Full sun
• Soil: Well-drained; intolerant of wet soil
• Flowers: Fragrant deep purple clusters
• Bloom season: Summer, with continued flowering possible into fall
• Foliage: Willowy gray-green leaves

Care and garden use

This low-maintenance shrub can be cut back in late winter to manage its size. Remove spent flower clusters to encourage further bloom. Avoid wet soil and watch for spider mites and nematodes.

Use as an accent or in grouped plantings, borders, wildlife gardens, rock gardens, foundation plantings, hedges, or suitably sized containers. Pair with Russian sage, daylily, or coneflower where growing conditions suit each plant.

Image credits: Ptelea, Buddleja davidii 'Black Knight' 2; User:BotBln, Buddleja davidii BlackKnight BotGardBln07122011A and Buddleja davidii BlackKnight BotGardBln07122011C; Raffi Kojian, Gardenology.org-IMG 6539 hunt10jun. All images licensed CC BY-SA 3.0. Plants naturally vary in appearance and may differ from the images shown.