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Annual Biennial

Isatis tinctoria

woad

An upright biennial, or sometimes a short-lived perennial, up to 1.2m high, with basal rosettes of oblanceolate leaves, stems with arrow-shaped leaves, and heads of yellow flowers in early summer, followed by brown seedheads in late summer; the flowers are good for bees, and the famous blue dye is obtained from the leaves

Other common names
ash of Jerusalem
common dyer's weed
see moredyer's weed
dyer's woad
Jerusalem ash

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Size
Ultimate height
1–1.5 metres
Time to ultimate height
1–2 years
Ultimate spread
0.5–1 metres
Growing conditions
Chalk
Clay
Loam
Sand
Moisture
Moist but well–drained, Well–drained
pH
Acid, Alkaline, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Green
Summer Yellow Green Brown
Autumn Green Brown
Winter
Position
  • Full sun
Aspect

West–facing or East–facing or South–facing

Exposure
Exposed or Sheltered
Hardiness
H7
Botanical details
Family
Brassicaceae
Native to the UK
Yes
Foliage
Deciduous
Habit
Columnar upright
Genus

Isatis can be annuals, biennials and perennials largely found on waste ground or dry, rocky areas. They have ovate to oblong shaped basal leaves and smaller, arrow-shaped, stalkless stem leaves. Loose racemes or panicles of yellow flowers are attractive to bees and these plants make a great addition to wildlife gardens.

Name status

Correct

Plant range
C & S Europe

How to grow

Cultivation

Grow in well-drained, preferably neutral or alkaline soil, in full sun; it tolerates poor infertile soils

Propagation

Propagate by seed, sown in autumn in a seed bed and transplanted in spring, or sown in spring in its intended planting place

Suggested planting locations and garden types
  • Prairie planting
  • Cottage and informal garden
  • Wildlife gardens
  • Flower borders and beds
Pruning

No pruning required

Pests

Generally pest-free

Diseases

Generally disease-free

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