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Key identifying traits
Large (3-8 inch wide) heart shaped leaves grow alternately on long
slender stalks
Entire plant is soft with short velvety hairs
Yellow to yellow-orange 5-petal flowers; ½-1 inch wide, solitary
generally in upper leaf axils
1-8 feet tall, rather linear in appearance with branching occurring in
upper portion of plant
Distinctive circular cluster of 12-15 seed pods produce purplish
brown, kidney shaped seeds
Biology and ecology
Tap rooted, summer annual reproducing by seed
Does not tolerate frost
700-17,000 hard-coated seeds per plant remain viable when buried for
more than 50 years
Native to Asia where fiber is used to make rope, bags, nets and
paper-introduced in North America in 1700’s as a potential fiber crop
Serious row crop (corn/soybeans) weed in the mid-West
Found infrequently in gardens, along fence lines and roadsides
throughout Washington
Leaves are horizontal by day, changing to nearly vertical at night
Control
Prevention – Learn to identify
plants; know your property; beware of contaminated vegetable seeds and
feed screenings
Biological – Some active in mid-West
Cultural – Healthy established vegetation helps, but plants can
produce seed under shade of a cover crop
Mechanical – Pulling, digging and cultivating prior to bloom will
kill plants; burn plants with seed pods-even immature pods will ripen
after cutting
Chemical –
Refer to the
PNW Weed Management Handbook for specific chemical recommendations |
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