Woad is a herbaceous perennial or biennial plant in the mustard family (Brassicaceae) native to Europe, southwestern Asia and Russia and grows on the stepp e s and desert zones of these areas. Woad was an important dye-producing plant starting in medieval Europe and was also used as a medicinal plant. It was eventually replaced by indigo. The Genus name derives from the ancient Greek word for the plant, ἰσάτις. Specific epithet from Latin means used in dyeing. Woad will grow 2 to 4 feet tall and spread 2 to 3 feet wide. It prefers alkaline to neutral moist well-drained soils with moderate fertility in full sun. It can be propagated by seeds and will self-seed in the landscape. It is a noxious weed in some western states and has experienced aggressive eradication. The first year, the plant grows as a basal rosette up to 1 foot tall. The second year, a leafy stalk rises above the foliage and produces a raceme of small 4-petaled yellow flowers. These are followed by showy seed pods. Being from arid areas of the world, it will not do well in the Southeast United States and should not beplanted in western states due to its aggressive nature. Insects, Diseases, and Other Plant Problems: No significant problems. Susceptible to club root.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist
Mature size
Height: 2 ft. 0 in. - 4 ft. 0 in. | Width: 2 ft. 0 in. - 3 ft. 0 in.
Growth rate
Medium
Maintenance
High
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Erect
Texture
Medium
Leaf color
Blue; Gray/Silver; Green
Leaf type
Simple
Leaf arrangement
Alternate; Whorled
Leaf shape
Rhomboidal
Leaf margin
Entire
Leaf feel
Smooth
Leaf size
3-6 inches long, < 1 inch wide
Hairs present
No
Leaf detail
Gray green to blue -green leaves form a basal rosette the first year and are arrow-shaped and 2 to 5 inches long. The alternate leaves on the flowering stem are smaller
Flower color
Gold/Yellow
Flower form
Raceme
Flower shape
Cup
Flower size
< 1 inch
Flower detail
Flowers are produced the second year in 4 to 6 inch long racemes. Eah flower is less than 1 inch and has 4 yellow petals
Bloom time
Spring
Fruit type
Siliqua
Fruit value
Showy
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Produces showy dark, penulant, dry fruit known as a silicle that does not split open and contains a single seed
Stem color
Green
Stem detail
Produces a single flowering stem that branches at the top
Wildlife & Ecology
Native status
Non-native
Origin
Europe, asia, Russia
Food & Medicine
Harvest time
Summer
Fruit type
Siliqua
Uses (ethnobotany)
Source of blue dye and used for a variety of medicinal purposes.