Isatis indigotica Seeds | Woad
LATIN NAME: Isatis indigotica
COMMON NAME: Woad
Plant Profile
Woad (Isatis indigotica) is an upright, biennial in the mustard family. Woad dips sprays of small, yellow flowers above blue-green leaves, the whole plant carrying the fine, tidy look of the old dye garden, the long taproot going deep into the soil. It is a plant of open, sunny, deep, rich, well-drained ground. For the small amount of care it requires, the return is remarkable.
Science & Biotechnology
Ban lan gen and its leaf (da qing ye, the historical source of indigo dye) share the bisindole alkaloids indigo and indirubin. In cell culture, indirubin inhibits replication of Japanese encephalitis virus with an IC50 around 14 micrograms per millilitre, apparently by blocking viral attachment, and protects mice from lethal challenge; related work shows it restores interferon signalling through the MAVS pathway in influenza-infected cells. Indirubin also inhibits cyclin-dependent kinases and GSK-3, and a derivative, meisoindigo, has been used clinically in China for chronic myeloid leukaemia. It remains one of the clearest examples of a dye-plant alkaloid becoming a drug lead.
Botanists studying the mustard family regularly include Isatis indigotica in comparative work, and the species also appears in horticultural trials aimed at gardeners and growers. Species like this one find a second career as research material, especially in propagation and breeding work.
Uses & Benefits
Beyond its ornamental appeal, Woad has the practical versatility that makes a plant worth growing from seed year after year. Woad is a quiet, useful plant of old dye garden and study collection. It is a quiet, useful plant of open, sunny, deep, rich, well-drained garden. Woad seeds grow readily in a fine, sandy mix on a bright sill. Once it has its roots down, it more or less looks after itself.
Woad is doubly famous: its leaves dyed Europe blue before indigo, and its root, Ban Lan Gen, with the leaf Da Qing Ye, is among the most-used Chinese antiviral folk herbs, taken in granules at the first sign of colds across East Asia.
Growing from Seed
Starting Woad from seed is simple and satisfying. Sow on the surface of a gritty, well-drained mix, cover lightly with fine compost, and maintain gentle, even moisture in a sunny position. When the young plants are big enough to handle, space them into pots or a nursery row and let them size up before their final move.
Our Take
The traditional uses covered above are what first made this species worth cultivating. Woad is the kind of plant that rewards a permanent spot. Even moisture while the seed is chitting is the main thing; afterwards it largely looks after itself.
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