Articles

Rain Garden Plants: Cardinal Flower

One-page informational sheet with details and pictures of cardinal flower (Lobelia cardinalis).
Updated:
August 25, 2021

Forms clumps of basal leaves. Has alternate, finely toothed, lance-shaped leaves on stalks; terminal spikes of showy, red, five-lobed flowers; and three lower petals and two upper petals. Needs disturbance. Attractive to insects and hummingbirds; long bloom period.

Height: 24 to 48 inches
Bloom color: Red
Bloom time: August to September
Hardiness zones: 3 to 9
Salt tolerance: Somewhat tolerant
Spreading habit: Clump-forming; self-seeds

Closeup of a Cardinal flower red flowering spike
 Photo credit: Ruth Benner, Penn State Extension
overhead view of a Cardinal flower plant showing the leaves
Photo credit: Jodi Sulpizio, Penn State Extension

Site Conditions

Sun: Sun/partial shade
Soil: Humus-rich soil; medium loam, clay loam, limestone-based, sandy, sandy loam, clay
Hydrologic zones: Wet/moist; inundation tolerant

Closeup of the individual flowers
Photo credit: Ruth Benner, Penn State Extension

Sources

Lady Bird Johnson Wildflower Center.

Mahr, Susan, “Cardinal Flower, Lobelia cardinalis," University of Wisconsin–Madison Division of Extension.

Missouri Botanical Garden, “Plant Finder."

Northern Neck Chapter of the Virginia Native Plant Society, “Salt Tolerant Northern Neck Native Plants."

Prepared by Jessica Chou, Jodi Sulpizio, and Constance Schmotzer.