Although quackgrass can reproduce by seed, it spreads primarily through a persistent and vigorous rhizome system.
Rhizomes are an underground network that spread out from the host plant just below the soil surface.
Along the rhizomes are buds, which set root and produce new plants To effectively control quackgrass, sufficient quantities of herbicide must be absorbed by the plant and transferred, or translocated, down into the rhizomes. Several postemergent herbicides can control quackgrass in broadleaf crops. The main advantage of using in-crop herbicides is that quackgrass may be suppressed while spraying for annual grass weeds and volunteer cereals. Roundup applied in the fall or in the spring before planting may give more consistent control of quackgrass than any of the postemergent grass herbicides. Several factors can influence the effectiveness of quackgrass control with Roundup.