Duluth, MN Tree Protection: Heritage & Protected Trees (2026)

Nominations can come from any citizen or resident of the city and go to the natural resources commission, which reviews them annually and recommends designations to the city council; the council makes the actual designation by resolution. Heritage trees can sit on public or private land, but if a nominated tree is on private property, the landowner must approve the nomination in writing before the commission can consider it. To qualify, a tree needs to meet at least one of five criteria: unusual trunk diameter or height for its species, a peculiar growth form giving it unique character, membership in a locally rare species, an age of at least 100 years as estimated by counting growth rings from an increment borer, or historic significance tied to a noted person, historic structure or significant event in Duluth's history.

The tree inspector keeps the official record of every designated heritage tree and its location. Once designated, a heritage tree on public property is protected from trunk girdling, from having more than 30 percent of a healthy tree's limbs removed, and from root damage, unless the tree inspector determines the tree has become a hazard to people or property, in which case the protections do not apply.