Origin: Eastern North America
Improvement status: Wild
Seeds per packet: ~550
Life cycle: Perennial
Blue vervain (also known as American vervain or swamp vervain) is beautiful perennial herb native to eastern North America with an array of culinary and medicinal uses. The seeds are edible and can be roasted and ground into a powder or cooked whole. The mildly bitter flavor (which some find pleasing) can be removed by leeching. The leaves make a fine tea substitute, with milder medicinal effects compared to the roots. According to Plants for a Future the plant is "antiperiodic, diaphoretic, emetic, expectorant, tonic, vermifuge, and vulnerary." It has pretty purple flowers and is well-suited to pollinator gardens and ecological restoration projects. Hardy to Zone 3. Vervain refers damp sites in full sun to part shade, but is very adaptable. It's liable to self-sow, so deadhead if you don’t want them to spread.
GROWING TIPS: Seeds should be sown in fall or winter or artificially cold stratified for 60+ days before sowing. Seeds should be surface sown, as they are quite small. Starting in pots is probably preferable due to small seed size.
Grows best on damp soils in full sun, but does fine in part shade and/or mesic soils. Prolific self-seeder, deadheading recommended where expansion is not desired. Very nice addition to a meadow or ditch edge.