Cardinal Flower (Lobelia cardinalis)
I was walking through the woods at Steinke Basin one summer day when I came to a bridge over a dry creek. It only runs in spring, but the channel still held its shape. Large trees stood on either side, far enough back to let in the light that cardinal flowers need. From the bridge I could see their red spikes lining the streambed in both directions, like flames tracing the old watercourse. In August along streambanks and seepage slopes, those narrow red spikes catch the eye even before you notice the hummingbirds working them. The flowers are built for that visitor. Each bloom forms a long tube with three lower lobes that act as a small landing shelf and two upper lobes that arch overhead. When a hummingbird leans in, its forehead brushes the anthers and picks up pollen, then carries it to the next plant. Bumble bees sometimes force their way in, and smaller bees may steal nectar from the sides, but they rarely move pollen where it needs to go.
In southern Wisconsin, cardinal flower grows best where the soil stays wet and the light is steady—sun to partial shade along creeks, marsh edges, and wet meadows. It will survive at a woodland edge, but deep shade weakens the plant and shortens the bloom. In restoration work, it adds height and late‑summer color to wet corridors, and it fills a nectar gap just when hummingbirds are building energy for migration.
Large butterflies such as cloudless sulphurs and swallowtails will visit when the bloom height and access suit them, though they are occasional guests rather than regular ones. The plant also supports the larvae of the pink‑washed looper moth, a small but meaningful piece of host value in a species better known for its pollinator role.
For wetland gardens, rain gardens, and riparian restorations, cardinal flower offers both beauty and function. It stands out in the landscape, and it earns its place by feeding the animals that depend on late‑season nectar.
Sources:
UW–Madison Extension – Cardinal Flower Profile
Illinois Wildflowers – Lobelia cardinalis
Missouri Botanical Garden – Lobelia cardinalis
Lady Bird Johnson Wildflower Center – Lobelia cardinalis
USDA Plants Database – Lobelia cardinalis
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