Culver’s Root can offer a strong upright accent to any perennial garden or prairie/savanna. It’s an elegant unbranched plant, reaching heights of 5′ or more with candelabra-like spikes of white flowers that open from the top down mid-summer. The small white flowers densely packed together can sometimes take on a purple hue; the contrast of these flowers against the dark green foliage is stunning. The central stem is round and smooth. Scattered along this stem are 3-7 whorled leaves. These leaves are up to 6″ long and 1½” across with serrated margins. They are ovate to narrowly ovate, and are either sessile or have short petioles. At the apex of the plant are several slender spikes of white flowers up to 8″ long, resembling a candelabra. The narrow tubular flowers are about ¼” long, from which 2 yellow or brown stamens are exerted. These flowers are crowded together all around each spike, blooming from the bottom up. They have no scent. The blooming period usually occurs from early to mid-summer, and lasts about a month. The tiny seeds can be carried several feet away from the mother plant by the wind. The root system consists of a central taproot and some rhizomes, which enable vegetative reproduction. The plant prefers full or partial sun, and moist to average conditions. Growth is best in rich loamy soil, although some sand or clay is tolerated. The leaves may turn yellowish green in bright sunlight or during a drought, otherwise they normally appear healthy and are not often bothered by disease. This plant has a tendency to flop over on slopes.
Culver’s Root grows in zones 3-8, as successfully in full sun as in partial shade (savanna conditions, up to 70% shade), and prefers moist, well-drained soil.