The nature of perennial pepperweed's creeping root system negates most mechanical control measures. Sprouts from root segments grow very rapidly, often resulting in flowering plants in the same year that the parent roots are cut in tillage operations. Mechanically cut roots are very resistant to drying. Roots exposed on the soil surface overwinter and will sprout the next spring. The crowns of established plants become enlarged and very woody.
Some farmers believe repeated mowing can suppress perennial pepperweed.
This form of control should not be dismissed without further trials, but mowing has to be very frequent with a very short stubble height for any chance of success in controlling this species. For most sites where it is established, such treatments are not practical. As we will expand upon later, mowing to remove the old accumulations of woody stems is a necessity before grazing or most herbicidal treatments can be applied. Once stem elongation begins, most herbivores will not consume the herbage of perennial pepperweed under any conditions. The only chance for herbivory is in the early spring when the leaves are just emerging.