Portland, ME Landscaping Rules: Tree Trimming (2026)

Chapter 29, Article I (Heritage Tree Protection Ordinance, Ord. No. 26-20/21) defines a Heritage Tree as any tree on private property in a designated historic district that is either on the Maine Big Tree List, is 24+ inches DBH of listed shade/native species (oaks, maples, hickory, elm, etc.), is 12+ inches DBH of listed ornamentals (dogwood, magnolia, etc.), or is a stand of rare native species like Atlantic White Cedar (Sec. 29-3). No person may remove a Heritage Tree on private property in a historic district without a tree-removal permit from the City Arborist (Sec. 29-5). 'Removal' includes excessive pruning and 'tree topping' — cutting limbs to stubs larger than 3" within the tree's crown (Sec. 29-3). Replacement caliper must equal the removed tree's DBH (Sec. 29-7); payment to the Tree Trust (Sec. 29-14) may be made in lieu of planting. Chapter 29, Article II governs ALL trees in public places: Sec. 29-18 requires a city arborist permit to plant, spray, fertilize, prune, or remove any street, park, or public-place tree; Sec. 29-20 requires owners abutting any street to maintain 10' clearance over sidewalks, 12' over streets, and 16' over truck routes; Sec. 29-24 prohibits excavating within 20 feet of any public tree without a written arborist permit.