100 Seeds Great Blue Lobelia Lobelia siphilitica Native Wildflower

Great Blue Lobelia is a native North American wildflower prized for its tall spikes of vivid blue-violet blooms that rise above bright green foliage from midsummer into early autumn. Each flower features a distinctive two-lipped shape with a white-striped throat, and the upright clumps add vertical interest to borders, rain gardens, and meadow plantings. This species is a classic choice for gardeners seeking a late-season bloomer that pairs beautifully with ferns, sedges, and other moisture-loving perennials.

Great Blue Lobelia performs best in consistently moist to wet soils and is an excellent selection for pond margins, stream banks, rain gardens, and low spots that stay damp. The nectar-rich flowers draw hummingbirds and a wide range of pollinators through the late summer season, while the seed heads that follow offer winter interest for birds. Plants grow as clumping perennials that return each year and can be divided every few seasons to maintain vigor. Space them where their cool blue tones can complement warmer-colored late bloomers.

Species: Lobelia siphilitica

Type: Herbaceous perennial

Plant_Habit: Upright clumping

Sun: Full sun to partial shade

Soil: Moist to wet, humus-rich

Days_to_Harvest: Not applicable

Zones: 4-9

Germination: 14-30 days at 65-75F; surface sow, light needed

Sowing: Start indoors 8-10 weeks before last frost

Spacing: 12-18 inches

Notes: Keep soil consistently moist; blooms midsummer to early fall