Pomona Tree Trimming Rules (2026): What You Need to Know

Pomona's tree regulations reflect the city's commitment to maintaining its urban canopy across a densely developed landscape of approximately 23 square miles. The landscaping standards in Title 18, Chapter 18.15 establish protection for significant trees on private property, defining a protected tree as any species with a trunk diameter of 12 inches or more measured at 4.5 feet above grade (diameter at breast height, or DBH). Removal of a protected tree requires a permit from the Planning Division, which evaluates whether the tree poses a genuine safety hazard, is diseased beyond recovery, or conflicts with an approved development project. Permit applications must include an arborist's report documenting the tree's condition and a replacement planting plan.

Replacement requirements typically mandate planting two 24-inch-box trees for each protected tree removed, with species selected from the city's approved street and landscape tree list. The replacement trees must be planted on the same parcel or, if space is insufficient, at an alternate location approved by the Planning Division. Routine maintenance pruning of private trees — removing dead branches, shaping canopy growth, or clearance pruning over walkways and structures — is permitted without a city permit provided no more than 25% of the tree's canopy is removed in a single season. Aggressive topping or lion-tailing that removes excessive canopy mass may be cited as a violation.

Street trees along public rights-of-way are the exclusive responsibility of Pomona's Public Works Department, which schedules regular maintenance cycles and responds to emergency situations involving fallen limbs or hazardous conditions. Residents may request street tree trimming or removal through the Public Works service request system but may not hire private contractors to work on street trees. Development projects that affect existing trees must submit a Tree Preservation Plan as part of site plan review, identifying all trees on or immediately adjacent to the project site, assessing health and structural condition, and detailing measures to protect retained trees during construction.

Pomona's tree canopy is particularly valued in neighborhoods near the Fairplex and along major corridors such as Holt Avenue and Garey Avenue, where mature trees provide critical shade and contribute to urban heat island mitigation. The city periodically updates its approved tree species list to favor drought-tolerant varieties consistent with Southern California's water conservation priorities.