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Baptisia 'Purple Smoke'
Purple Smoke Baptisia
Hybrid of garden origin (B. australis × B. alba); bred at North Carolina Botanical Garden
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Key Features
Attracts PollinatorsAttracts ButterfliesAttracts HummingbirdsDeer ResistantDrought Tolerant
Native to North America
Maintenancevery low
Overview
Baptisia 'Purple Smoke' is an upright, bushy, clump-forming herbaceous perennial reaching 36–48 inches (90–120 cm) tall with a spread of 36–48 inches (90–120 cm). This hybrid, a cross between B. australis and B. alba, was bred by Rob Gardner at the North Carolina Botanical Garden. Stems are stout, dark charcoal-gray to nearly black, providing structural contrast against the foliage. Leaves are trifoliate with leaflets 1.5–3 inches (4–8 cm) long, emerging with a blue-green cast and maturing to gray-green by mid-summer. Upright racemes 10–16 inches (25–40 cm) long bear smoky violet to dusky lavender, pea-shaped flowers 0.8–1 inch (2–2.5 cm) long in May–June. Flower color is intermediate between the indigo-blue of B. australis and the white of B. alba, with a muted, smoky quality. Inflated seed pods develop after bloom, turning dark brown to black and persisting through winter. The deep, woody taproot makes transplanting difficult once established. Growth is slow during the first 2–3 establishment years. In rich, moist soils or partial shade, stems may splay outward by mid-summer. Foliage blackens after the first hard frost.
Native Range
Baptisia 'Purple Smoke' is a hybrid of garden origin, bred at the North Carolina Botanical Garden from the cross B. australis (native to eastern North America) × B. alba (native to central and eastern North America). Both parent species occur in prairies, meadows, and open woodlands.Suggested Uses
Planted in prairie gardens, native plant borders, and mixed perennial plantings at 36–48 inch (90–120 cm) spacing. The smoky violet flowers and dark stems add a muted, cool-toned element versus the clear blue of B. australis. Combines with B. australis, B. alba var. macrophylla, and B. 'Carolina Moonlight' for a multi-color Baptisia display. Not suitable for containers due to the deep taproot.How to Identify
Appearance
Size & Dimensions
Height3' - 4'
Width/Spread3' - 4'
Reaches mature size in approximately 5 years
Bloom Information
Smoky violet to dusky lavender pea-shaped flowers appear on upright racemes 10–16 inches (25–40 cm) long in May–June. Individual flowers are 0.8–1 inch (2–2.5 cm) long. Bloom duration is 3–4 weeks. Inflated seed pods develop after flowering, turning dark brown to black and persisting through winter.Detailed Descriptions
Flower Description
Smoky violet to dusky lavenderFoliage Description
Blue-green to gray-green, trifoliateGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Plant in well-drained to average soil in full sun. Tolerates poor, dry soils once the deep taproot is established. Lean, well-drained soils produce the sturdiest stems; rich, moist soils or partial shade cause stems to splay. The deep taproot makes transplanting difficult; plants should be sited in their permanent location. Growth is slow during the first 2–3 years while the root system develops. Few pest or disease problems occur. Nitrogen fixation through root nodules reduces fertilization needs. Japanese beetles occasionally feed on foliage and flowers.Pruning
Allow spent flower racemes to develop into the dark seed pods for fall and winter structural interest. If stem splaying is a concern, cut back by one-third in late May before bloom to reduce height. Cut all stems to 2–4 inches (5–10 cm) above ground in late fall or early spring. The deep taproot cannot be divided without killing the plant.Pruning Schedule
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fallearly spring