Boulder, CO Landscaping Rules: Tree Trimming (2026)

Section 6-6-5, "Spraying and Pruning," sits in Chapter 6-6, "Protection of Trees and Plants," and controls maintenance work on any tree or plant growing on city-owned or city-controlled land, including street trees in the public right-of-way. Subsection (a) bars any person other than the city manager from spraying, mulching, fertilizing, treating, removing, destroying, breaking, cutting, or pruning a living plant or any part of it on city property without first obtaining the manager's permission. Subsection (b) constrains anyone the manager does authorize to cut or prune: that work must be performed exactly in the manner the manager prescribes, not by the contractor's own judgment.

The section works alongside Section 6-6-3, which gives the city manager general authority to supervise reforestation and regulate planting and pruning timing and method on city property, and Section 6-6-6, which requires that any tree removal, damage, or attachment of hardware to a right-of-way tree be performed only by International Society of Arboriculture certified contractors licensed in the City of Boulder. A commercial operator who wants to cut, prune, remove, or apply pesticides to trees on public or private property in the city for pay must separately hold a license under Chapter 6-6, per Subsection 6-6-6(f).

Because Section 6-6-5 states no fine of its own, a violation defaults to the citywide general penalty in Section 5-2-4, "General Penalties," which authorizes a fine of up to $2,650 per violation, incarceration of up to ninety days, or both, for any code provision that does not set its own penalty.