Problem: Quackgrass (Lawns)
Elytrigia repens This cool-season perennial, also called couchgrass or witchgrass, spreads extensively through the lawn by long white underground stems. It reproduces by seeds and these underground stems. The seeds may lie dormant in the soil for up to 2 years. Quackgrass is found most frequently in fertile, newly seeded lawns. It grows much more rapidly than grass seedlings, often crowding them out.
Quackgrass is difficult to control in lawns. Hand-digging is not a practical solution, because any rhizome pieces left behind will generate new plants. If the entire lawn is infested with it, the lawn will need to be killed and another planted. If only isolated areas are infested, kill them and replant those spots.