Perennial weed invasion is favored by the lack of tillage during the life of a stand.
Perennial weeds can be extremely difficult to control in established crops.
Proper site selection is a key component of perennial weed control. Avoid planting in fields heavily infested with perennial weeds such as quackgrass, dandelion, or Canada thistle. Prior to planting, control these weeds through crop rotation, mechanical control, or with nonselective herbicides. An application of Roundup in the fall, prior to planting, is effective. Plowing or multiple discings prior to planting can also control noncreeping perennial weeds, such as dandelion or buckhorn plantain.