||Winter annual, biennial,
or short-lived perennial
||Spring or Fall
||April-May (after the
|| Seeds Mature:
is native to southeastern Russia and currently exists on six continents.
Anciently, it was believed to have medicinal
properties and warriors used it to paint themselves with the blue
extract. Later, it was grown and used as a textile dye and was transported
from Europe to America for that purpose. In the early 1900's, It was introduced
into the West as a contaminant in alfalfa seed. There is no record of
it being planted on purpose in the West.
of the mustard family produces an average of 350-500 seeds per plant,
with some plants producing well over 10,000 seeds in one year. In one
instance, a population of dyer's woad grew from 2 acres to 100 acres in
2 years, just by seed dispersal and establishment. The seeds alone show
little dormancy, but seeds left in the fruit may persist. Dispersal by
wind is limited, except for those that may be moved along the surface
of the snow. Most long-range dispersal occurs by vehicle, flowing water,
birds, and contaminated feed.
plant starts out as a low-lying rosette.
Winter chilling is necessary for the plants to bolt
and produce the beautiful dome of bright yellow flowers. Average stem
growth during the bolting stage has been measured at a rate of 4 inches
per week. Flowering is seen as early as April, with seeds maturing in
June or July. Dyers woad produces a tap root 3-5 feet long.
Loss of forage,
alteration of natural plant community.
Used as a
blue dye in textiles.
doesn't need a human disturbance in order to invade a site. Although it
prefers rocky soil with limited water holding capacity, it is very prolific
and will grow in a variety of places. It can be found in rangelands, forests,
grain fields, pastures, waste areas, roadsides, orchards, and in cultivated
again, multiple tools can and should be used in the control of dyer's
• One of the simplest and most effective control methods is hand-pulling.
In parts of Utah this method has been used by high school students and
other volunteers. This is most effective with small populations and should
be done 2-3 times a year for several years to be effective. It is safe
to leave the pulled plants on site if there are yellow flowers still attached
to the plant (green seed pods may be visible). If flowers are not present,
the seed are developed enough to germinate. These plants should be hauled
to the dump.
• A biological control agent (a fungal rust known as Puccinia thlaspeos)
has been found to be effective in keeping dyer's woad populations in check.
• Herbicide application is most effective in the rosette stage (example
herbicides: 2-4,D, Escort, Ally, Telar [look
at herbicide label: free search]).