OSU Controlling perennial weeds before planting brambles is important to minimize competition between the crop and weeds during the establishment and later years of production. Wild brambles, such as wild blackberry, serve as a source of disease innocuous to the crop and must be completely eliminated from the field and immediate surroundings prior to planting. Quackgrass, Canada thistle, wild brambles and field bindweed spread and reproduce mainly by underground root stocks or rhizomes.
Perennials are difficult and costly to control once a crop has been planted.
Herbicide application must be timed correctly and the right rate used. The following treatments will provide the best control of perennials and will control emerged annual weeds as well. Quackgrass and many broadleaf perennial weeds are best controlled with fall applications. Do not plow after harvest. An extended period of drought just before spraying may adversely affect control.