Each quackgrass plant has the potential to produce a high number of seeds and is ranked in the 11-1000 seeds per year category. Quackgrass may flower and produce viable seed more than once a season. If combined, the populations would cover an area of more than 11 but fewer than 50 hectares. These plants are found in mid-successional sites disturbed in the last 11 to 50 years. Quackgrass has the potential to retard natural succession in the park by competing for secondary successional resources.
Quackgrass is difficult to control, and a limited number of control methods are available.
An important consideration in controlling this species is that the seeds have the potential to remain viable in the seed bank for up to 10 years, and it can vigorously spread by rhizomes. Prior to applying any control method, it is important to determine if enough desirable plants are present to replace the controlled plants. If desired vegetation is scarce or absent control will be of little value. An alternative may be to follow control with seeding of desirable species. Another consideration is that most control methods harm other plants and the resulting disturbances favor reinvasion by quackgrass or other exotic species.