DUBUQUE, Iowa (AP) -” An invasive weed that can grow up to 7 feet tall has been found in nearly half of Iowa’s counties, and experts say farmers need to act quickly if the plant is found in their fields.

Bob Hartzler is a professor of weed science at Iowa State University. He tells the Telegraph Herald that the species known as Palmer amaranth shouldn’t be ignored and has the potential to drive farmers out of business. The weed prominently appeared in the region’s cotton fields in the 2000s. It was categorized as a “super weed” because of its ability to quickly grow and its resistance to many herbicides.

In 2013, the weed was spotted in five Iowa counties. As of October, it had been seen in nearly half of Iowa’s 99 counties.