Duluth to remove Cork trees due to invasive classification

City officials said Friday, crews will be removing male Amur Cork trees from 4th Street due to the tree being classified as invasive. There are 18 trees that will be removed by the Duluth Park Maintenance crews in the coming weeks.

According to a press release, the trees were planted during the St. Louis County and City of Duluth 4th Street Reconstruction Project. The project reconstructed two miles of 4th Street for the first time in 30 years and replaced the water, gas, and sewer lines, some of which were more than 100 years old.

Official said various kinds of trees were planted in the boulevards as a part of the project, including male Amur Cork trees. The species was recommended at the time due to its ability to survive in an urban environment. Only males were planted so that the non-native tree would not be able to spread. After receiving reports of Amur Cork trees outside of the ones planted in the reconstruction project, the Minnesota Department of Agriculture investigated.

“Based on the evidence provided by the Department of Agriculture, the City sees the potential for the male Amur Cork trees to become female which would make them invasive,” City of Duluth Forrester Clark Christensen said in the press release. “The City will be removing the Cork trees and replanting a noninvasive tree in its place to remediate this risk."