Stems: 1 to 3 feet tall, simple below, branched above.
Leaves: Basal leaves form a rosette 8 inches long, stalked,
widest near apex, bearing soft fine hairs; leaves of the stem shorter,
alternate, lanceolate, sessile, and with a pair of short basal lobes
clasping the stem, mostly entire and without hair.
Flowers: Small, four sepals and petals, yellow, about 1/4-inch
across. Borne in dense clusters on the stem tip. Flowering period
is from April to July.
Seeds: Seeds are contained in 3/4-inch tear-shaped, purplish-brown
Dyer's woad can be either perennial or biennial. It is cultivated
for blue dye. It thrives in light sandy soil and forms dense stands
on grazing and marginal farm lands. It spreads by seed into dry
Control: Prevent new infestations.
- Biological: Sheep have been relatively ineffective. A
recently discovered pathogen may have application as a host-specific
- Chemical: Most effective before the plant sends up a
stem. After the flower stem appears, herbicides have little effect.
Consult you local weed board for current regulations and other
- Mechanical: Hand pull or dig out individual plants. Cultivate
early in the spring to prevent it from getting a start. Destroy
new seedlings in the fall.
Report all sightings to your local