Lobelia Siphilitica (Great Blue Lobelia)

Blue Cardinal Flower, Great Blue Lobelia

Lobelia siphilitica (Great Blue Lobelia) is a native perennial with an upright, clumping habit, featuring lance-shaped green foliage and spikes of rich blue to violet-blue tubular flowers from mid-summer into early fall. It naturally grows in moist to wet meadows, stream edges, and low woodland areas, and is valued for its late-season color and pollinator appeal.

Type: Perennial
Mature Size: 12–18" W × 36–48" H
USDA Zones: 4a–9b
Form: Upright, clumping

Light: Full sun to part shade
Soil / Water: Rich, moist to wet soils; moderate to high water, prefers consistently moist soil
Bloom Time / Length: Mid-summer to early fall; long-lasting (4–8 weeks)

Wildlife: Bees, butterflies

Features & Landscape Uses:
Excellent for rain gardens, moist borders, woodland edges, pond margins, and native plantings. Its tall blue flower spikes provide strong vertical color late in the season and pair especially well with other moisture-loving natives such as cardinal flower.

Care:
Keep soil evenly moist and do not allow plants to dry out, especially in sunnier sites. It may self-seed in favorable conditions, and clumps can be divided in spring. Best performance comes in fertile soil with steady moisture. 

Plant type

Perennial

Height

36-48"

Width

12"-18"

Hardiness zones

4–9

Growth rate

Moderate

Bloom time

Early Fall, Late Summer, Mid Summer

Leaf color

Green

Fall color

Green

Attracts

Bees, Butterflies, Hummingbirds

Soil

Clay, Moist well-drained, Rich, Wet Area

Drought tolerant

No