Russian Knapweed

is a creeping perennial that reproduces from seed and vegetative roots. It produces 50 to 500 seeds per shoot with a root growth rate of 12 square yards in two growing seasons.
forms dense, single species stands due to competition and allelopathy (biochemicals it produces that inhibit the growth of other plants).
is toxic to horses and not desired forage for cattle. Eliminating knapweed will allow grasses to re-establish, however, planting a dry land grass in non-irrigated areas or pasture mix to irrigated areas not previously seeded will provide optimum benefit and use for grazing livestock.

Frequent mowing will place stress on the plant, however is not considered effective as the root of this plant will continue to thrive.
Disking knapweed will prompt patches to grow at a faster rate and spread quickly to non-infested areas.
There are herbicides on the market that, if applied correctly, have proven effective. Older, more established stands should be monitored annually to assure seed bed has diminished and/or disturbance has not prompted re-emergence. Products such as Milestone, Redeem, Transline, Curtail, and Telar are effective when applied at the bud to bloom stage and in the fall. Always read and follow the label when using any herbicide.
Controlling Russian knapweed in an irrigated broadleaf crop is difficult. It is best to consult your field advisor to carefully plan control options based on your specific crop rotation schedule.