Common Name: American blue vervain
Type: Herbaceous perennial
Native Range: Eastern North America
Zone: 3 to 8
Height: 2.00 to 6.00 feet
Spread: 1.00 to 2.50 feet
Bloom Time: July to September
Bloom Description: Purplish-blue
Sun: Full sun
Water: Medium to wet
Suggested Use: Naturalize, Rain Garden
Tolerate: Wet Soil
Easily grown in average, medium to wet soils in full sun. Typically forms colonies in the wild by both thick, slowly spreading rhizomes and self-seeding. May self-seed in gardens in optimum growing conditions. Can be short-lived.
Blue vervain is a Missouri native perennial which commonly occurs in wet meadows, wet river bottomlands, stream banks, slough peripheries, fields and waste areas throughout the State except for the Ozark region where it is uncommon (Steyermark). It is a rough, clump-forming perennial with a stiff, upright habit which typically grows 2-4' tall (less frequently to 6') on square hairy stems which typically branch above. Features candelabra-like inflorescences of erect, slender, pencil-like spikes (2-6" long) of tiny, tubular, 5-lobed, densely-packed, purplish-blue flowers (1/8" wide) which appear over a long July-September bloom period. Flowers on each spike bloom bottom to top, only a few at a time. Lance-shaped, sharply toothed, green leaves (to 6" long).
No serious insect or disease problems.
Borders, meadows, prairies, native plant gardens or informal/naturalized areas.