great blue lobelia

Lobelia siphilitica


Lobelia siphilitica var. ludoviciana
Lobelia siphilitica var. siphilitica

Other Common Names

blue Cardinal flower

Plant Type

Herbaceous Wildflower

Life Cycle


Typical Size

3-4 ft. tall
1-1.5 ft. wide

Tolerant of

Occasional Flooding

Inolerant of

Dry Soil


By seed, By division

Plant Propagation Notes

Seeds require cold moist stratification for 60 days to germinate. Seeds also require sunlight to germinate and should not be covered by soil.

Plant Planting Notes

Provide about 1.5 ft spacing. Use in wet areas such as rain gardens or pond/stream edges.


Slugs and snails can be an issue due to the wet environment these plants like to grow in.

Wildlife Benefits

Nectar/pollen source for pollinating insects, Nectar source for hummingbirds


Leaves alternate, lanceolate with dentate margins.


Bright blue tube-shaped flowers on a raceme.


All parts of the plant has low toxicity if consumed.

Lobelia siphilitica

USDA Hardiness Zones

4, 5, 6, 7, 8, 9

Light Exposure

Full Sun, Part Sun/Shade, Full Shade

Soil Moisture


Soil Drainage

Well-drained, Poorly Drained

Native in South Carolina?


Plant Native Habitat

Wet habitats such as streambanks, meadows, ditches, bottomlands, and forests.

Global Conservation Status (NatureServe)

Secure (G5)

Federal Conservation Status (USFWS)

Not Listed

Distribution Notes

Rare in the South Carolina mountains. Absent from the coastal plain, sandhills, and piedmont.