Where in the OLL?

The cardinal flower is a seed- and fruit-bearing plant belonging to the angiosperm group. It is located at the botanical and the wetland part of the Outdoor Learning Laboratory. The cardinal flower is in the botanical part of the garden to provide an opportunity for students to learn about a variety of plants and native pollinators. The botanical part of the garden provides an opportunity for students and the public to learn about a variety of plants that grow in the Greenfield area.

Plant growth form

The Cardinal Flower is an herb. This perennial is a herbaceous plant with rhizomes that overwinters with small clusters of rosettes three to six inches in diameter. The leaves are clumped closely together and are a dark and shiny green. It grows 30-36 inches tall and 10-18 inches wide. The leaves are alternate, toothed, lance-shaped and pointed at both ends. Green parts of the plant are visible throughout the year. As noted above, the plant overwinters with dark, shiny green leaves in a rosette. In late spring a single, large, strong flower stalk begins to grow out of the center of each rosette. The stalk continues to grow at its tip, even as flowers begin blooming in July or August, producing more flowers along its length. Flowering can continue into September, or even into October.

Flowers, fruits & pollinators

The cardinal flower’s tubular flowers are 2-lipped, with the three lobes of the lower lip appearing more prominent than the two lobes of the upper lip. This flower blooms from July to September, except when the fall is warm. It had a bright color of scarlet red. The fruits are ready in the fall. The floral arrangement is perfect. This means that the stamen and the pistil are in the same flower. The flower occurs as a spike. A spike is an unbranched, indeterminate inflorescence, similar to a raceme, but bearing sessile flowers (sessile flowers are attached directly, without stalks).

Ideal location, conditions & cultural needs

These plants want to maintain “wet feet” and, in our climate, are happy in shade, especially late in the day, to avoid the hot, dry sun from the west. This plant is best suited for wet soil, living along stream or pond edges. Little maintenance is needed for this plant. One can separate the new rosettes from their parent plant in the spring to space them farther apart.

Planning & maintenance

Cultivars & propagation

There are a few plant varieties: “Alba” has white flowers, “Heather Pink” has soft pink flowers, “Angel Song” has salmon and cream flowers, and “Rosea” has pink flowers. This plant can be propagated by seed or by separating the new rosettes from their parent plant in the spring and spacing them out.

Pests & pathogens

There do not seem to be any of note. According to the Missouri Botanical Garden website, Lobelia cardinalis is tolerant of rabbits and deer. No serious insects or disease problems impact this plant. Snails and slugs may damage foliage. The snail and slug damage does not seem to be enough of a problem to require intervention.

Landscape & ecosystem

The cardinal flower’s bright scarlet red is a big attraction in the summer time. It provides a source of nectar to its hummingbird pollinators and to its nectar thief spicebush swallowtails.

Human uses

American Indians used the roots as a tea for stomach aches, syphilis, typhoid, worms. Tea made from leaves used for colds, croup, nosebleeds, favors, headaches, and rheumatism. Historically, this plant is considered a substitute for Lobelia or Indian-Tobacco but with weaker affects.