Great Blue Cardinal Flower 'Lilac Candles' is a Missouri native perennial that brings cool, sophisticated color to moist garden spaces from July through September. This clump-forming beauty produces dense spikes of light to dark blue, tubular flowers with distinctly prominent lower lips, creating striking vertical interest in rain gardens and naturalized areas. Hardy from zones 4 to 9 and reaching just 12 to 18 inches tall, it thrives in moderate moisture and tolerates everything from full sun in cool climates to heavy shade, making it adaptable to many garden conditions. Low maintenance and beloved by pollinators while ignored by deer, this variety handles wet soil with ease and even self-seeds to form attractive colonies when conditions suit it.
Partial Sun
Moderate
4-9
18in H x 12in W
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Low
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The 'Lilac Candles' cultivar surprises gardeners with its ability to flourish in average garden soils as long as moisture stays consistent, freeing you from the need to engineer perfect boggy conditions. Its two-lipped flowers, where the three lower lobes steal the show from the two upper ones, create an architectural quality that looks stunning in tall drifts along stream edges or in rain gardens. Unlike the species, which demands constant moisture, this selected form shows real flexibility about soil richness while still celebrating wet conditions.
Great Blue Cardinal Flower serves as a striking addition to rain gardens and naturalized plantings where its tall spikes of blue flowers anchor the composition. Its native status makes it valuable for ecological gardening and supporting native pollinators. Use it to soften pond edges, stabilize wet areas, or create cottage-style drifts in shaded borders where moisture naturally collects.
No timeline data available yet for this variety.
Seed germinates best at 65 to 75 degrees Fahrenheit. Start indoors 6 to 8 weeks before your last spring frost to give seedlings time to develop before transplanting.
Transplant seedlings outdoors after the last frost date has passed and soil has warmed. Space plants 9 to 12 inches apart to allow room for mature width. Harden off seedlings gradually over 7 to 10 days before planting in their final location.
Divide clumps in spring to rejuvenate mature plants and prevent overcrowding. Deadhead spent flower spikes if you prefer a tidier appearance and want to prevent self-seeding, or leave them standing if you enjoy natural reseeding and the architectural interest of dried seed heads through fall.
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“Lobelia siphilitica itself is a Missouri native, thriving in the moist margins of streams, swamps, and wet meadows across the state. The 'Lilac Candles' cultivar represents a selection refined for garden performance, bred to tolerate slightly drier average soils while maintaining the native species' ornamental charm and ecological value. This selected form carries the heritage of native plant conservation while offering gardeners more practical growing conditions than the species alone.”