Common Name: Culver's root
Type: Herbaceous perennial
Family: Plantaginaceae
Native Range: North-central and northeastern Asia
Zone: 3 to 8
Height: 3.00 to 5.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: July to September
Bloom Description: Lavender-lilac
Sun: Full sun
Water: Medium
Maintenance: Low
Flower: Showy
Attracts: Butterflies
Culture
Easily grown in average, medium moisture, well-drained soil in full sun. Tolerates part shade including sun-dappled conditions. Stems my flop in too much shade. Best performance occurs in sharply-drained soils with consistent, regular moisture. Remove spent flower spikes to encourage additional bloom. Plants may be cut back to basal growth after flowering. Propagate by seed or division.
Noteworthy Characteristics
Veronicastrum sibiricum, commonly known as Culver’s root, is a large, upright, rhizomatous perennial of the figwort family that is native to grassy slopes and thickets in China, Japan, Korea, Mongolia and Russia (Siberia). This plant produces several upright leaf stalks (each rising to 3-5’ tall) clad with horizontal whorls of oblong to broadly linear, sharply-toothed, short-petioled, serrate-margined, gray-green leaves (each leaf to 6” long and to 2” wide). Each whorl typically has 4-6 leaves. Leaves have a coarser texture than the leaves on Veronicastrum virginicum. Leaf stalks are topped by slender, tapered, candelabra-like, terminal spikes (to 8” long) of lavender-lilac salverform flowers which bloom in late summer to early fall (July-September). Each flower has a long slender tube and 4-5 short lobes. This plant resembles a tall veronica and was once included in the genus Veronica. Veronicastrum has leaves in whorls and corollas with tubes that are much longer than the lobes, whereas Veronica has opposite leaves and corollas with tubes shorter than the lobes.
Genus name comes from the genus name Veronica (Christian legend claims Saint Veronica gave her veil to Christ to wipe his forehead while he was carrying the cross to Calvary) and astrum meaning star or incomplete resemblance.
Specific epithet is in reference to this plant being in part native to Siberia.
The origin of Culver’s root is uncertain, but may refer to an early American physician from the late 17th to early 18th century (Dr. Culver or Dr. Coulvert) who reportedly used the U.S. species Veronicastrum virginicum in his practice for its laxative properties.
Problems
No serious insect or disease problems. Root rot may occur in wet, poorly-drained soils.
Uses
Cottage gardens, border backgrounds, woodland margins. Best in groups or massed. Naturalize in prairie areas.