Quackgrass is one of the most troublesome perennial grasses in the northern U.S. Its extensive root system consists of long white underground stems that may grow 5 feet or more in a single growing season. Narrow, bluish-green blades grow on stalks 1 to 3 feet tall. Wheatlike spikes produce seeds from May to September. The seeds can survive in the soil for up to 4 years, but most germinate in the spring within 2 years. The underground creeping rhizomes also send up new shoots. Quackgrass tolerates any type of soil and can crowd out more desirable plants.
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.