There's a reed taking over Minnesota wetlands that isn't from around here. Invasive phragmites, a non-native strain of common reed, can grow up to 18 feet tall and crowds out native plants, sucking down so much water it can turn a healthy marsh into something closer to a dry meadow. It's already established in 49 states.
Minnesota isn't there yet, according to Daniel Larkin, a professor and extension specialist with the University of Minnesota's Aquatic Invasive Species Research Center (MAISRC). "We're in this kind of unique spot where we have a lot of it, but where there are management options that are effective," Larkin said. He credited a statewide network of partnerships among counties, watershed districts and the Department of Natural Resources for keeping the plant containable — a coordinated, statewide phragmites control program he said no other state has, to his knowledge.
The numbers back up the urgency. As of June 2025, researchers had verified roughly 2,350 invasive phragmites populations statewide, but those patches together cover only about 184 acres — a small footprint that still gives crews a real shot at knocking populations back before they merge into unmanageable stands.
The state has treated the plant as a priority since its statewide control program launched in 2019, and the DNR has put $390,000 in Great Lakes Restoration Initiative funding toward the effort since then. Non-native phragmites also carries a legal designation as a Prohibited Invasive Species in Minnesota, meaning it's a misdemeanor to possess, transport or introduce it without a permit for control, disposal, research or education.
Getting rid of it isn't a one-and-done job. The Department of Natural Resources recommends mowing infested areas three to five times a season to knock density down, paired with herbicide treatments — usually glyphosate or imazapyr — followed by mowing to clear the dead growth. Multiple years of follow-up are typically needed to keep the plant from re-establishing from its root system.
The pitch from researchers is essentially: act now while the plant's footprint is still small, because the alternative closes the door on cheap, effective control for good.