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Boulder County, CO Landscaping Rules: Tree Trimming (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified July 2026

Key Facts

Private trimming permit
Not required
Defensible zones
Wildfire Zone 1 and Zone 2
Noncombustible zone
First 0-5 feet
Manage fuels to
Up to 100 feet
Compliance paths
Building Code or Wildfire Partners

Summary

Boulder County does not require a permit to trim your own trees. In Wildfire Zones 1 and 2, the county requires vegetation thinning and defensible space around structures under its wildfire building rules.

City-specific rules exist: Boulder, and Longmont have their own tree trimming rules that differ from Boulder County's county-level regulations. If you live in one of those cities, check the city-specific page instead.

Full defensible space is required in Wildfire Zone 1 – West County and Wildfire Zone 2 – East County. Full defensible space is NOT required in Wildfire Zone 3 – East County.

Full Breakdown

There is no general county tree-trimming permit for private landowners in unincorporated Boulder County. Routine pruning and thinning are allowed and, in the wildland-urban interface, encouraged. Where defensible space applies (new builds, additions over 200 sq ft, and larger accessory structures in Wildfire Zone 1 – West County and Wildfire Zone 2 – East County), the county requires vegetation and fuels management around the home: the first 0-5 feet noncombustible, with fuels managed outward toward 100 feet based on slope. Homeowners meet this through the Building Code path or a Wildfire Partners assessment. Trees in the public right-of-way or on Open Space are managed by the county, not residents.

Violations & Fines

Defensible-space vegetation work is verified at building-permit inspection; failing inspection blocks permit approval until the fuels reduction is completed.

Frequently Asked Questions

Do I need a permit to trim trees on my land?
No county permit is needed to prune or thin trees on your own property. In wildfire zones, fuels reduction near structures is required when you build or add on.
What is the 0-5 foot zone?
The county's defensible-space rule keeps the first five feet around a home noncombustible, using rock or gravel, to reduce ignition from embers and surface fire.

Sources & Official References

Other rules in Boulder County

All Boulder County rules

Compare Boulder County to another location·View the Colorado landscaping rules overview

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