About
Isatis tinctoria, woad, is an upright biennial or short-lived perennial to 1.2 m with basal rosettes of oblanceolate leaves, arrow-shaped stem leaves and heads of small, yellow flowers in early summer followed by distinctive, hanging, brown seedheads in late summer. The leaves are the historic source of the blue dye used in ancient Britain. Excellent for bees.
About the genus
Isatis are annuals, biennials and perennials of waste ground and dry, rocky areas, with ovate to oblong basal leaves and arrow-shaped stem leaves. Loose racemes or panicles of small, yellow flowers are attractive to bees. Best known for Isatis tinctoria, the source of the ancient blue dye woad.
Growing conditions
SunlightFull sun
Soil typeChalk, Clay, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureMoist but well-drained, Well-drained
AspectWest-facing, East-facing, South-facing
ExposureExposed, Sheltered
UK hardinessH7
Plant details
Plant typeAnnual Biennial
HabitColumnar upright
FoliageDeciduous
Height1-1.5 metres
Spread0.5-1 metres
Time to full height1-2 years
Suggested usesPrairie planting, Cottage and informal garden, Wildlife gardens
Native toC & S Europe
Care notes
CultivationGrow in well-drained, preferably neutral or alkaline soil, in full sun; it tolerates poor infertile soils
PruningNo pruning required
PropagationPropagate by seed, sown in autumn in a seed bed and transplanted in spring, or sown in spring in its intended planting place
Pest resistanceGenerally pest-free
Disease resistanceGenerally disease-free