8 county-level rules, plus city-specific rules for 4 cities in Washington County, Oregon.
Verified from official government sources
Washington County regulates nuisance vegetation under Chapter 8.20 of the Code of Ordinances. Cities set specific grass height limits (typically 10 inches). Oregon state law (ORS 105.550–105.570) authorizes municipalities to enforce weed control and nuisance vegetation standards.
Property owners in unincorporated Washington County are responsible for maintaining trees on their property and adjacent right-of-way. The Community Development Code (CDC 407) establishes landscape design standards including tree maintenance requirements for development projects.
Hillsboro Municipal Code 6.16.020 and 6.28.010 — Code Compliance: Tall Grass, Weeds, and Roadside Trees
Tall Grass, Weeds, and Roadside Trees — HMC 6.16.020 & 6.28.010 requires the cutting and removal of noxious vegetation, such as blackberries, and grass longer than 12 inches. Property owners are also responsible for right-of-way property adjacent to theirs. Your trees must be trimmed 8 feet above sidewalk level and 15 feet above street level. Any shrubbery must not impede sidewalk areas. Visit ...
Tree removal in unincorporated Washington County is regulated by the Community Development Code. The county's landscape design standards (CDC 407) include tree preservation and replacement requirements. Clean Water Services approval is needed for trees in sensitive areas.
Washington County enforces weed abatement under ORS 105.550-105.570 and county nuisance provisions. Vacant lots in unincorporated Aloha, Metzger, Cedar Mill, and Bull Mountain receive targeted enforcement, especially during late-spring growth peaks.
Washington County does not impose mandatory outdoor watering restrictions in most years. Water supply is managed by various providers across the county. Oregon Water Resources Department (OWRD) manages water rights under ORS 537. The Tualatin Basin is generally water-rich west of the Cascades.
Rainwater harvesting is permitted in Washington County for outdoor irrigation and non-potable use under Oregon Water Resources Department policy. Systems over certain thresholds require plumbing permits under OAR 918. Many Bethany and Hillsboro HOAs encourage rain barrels.
Washington County and Metro encourage native Willamette Valley plantings for stormwater and habitat. Tualatin SWCD offers the native plant sale. Clean Water Services requires native plantings in vegetated corridors along streams.
Washington County allows artificial turf on residential properties without a specific permit. Stormwater runoff from impervious turf may trigger Clean Water Services rules if over 1,000 sq ft disturbed or grading involved.
4 cities in Washington County have their own landscaping rules rules. Each link goes to that city's dedicated page with code citations.
4 verified rules • Grass Height Limits, Tree Removal & Heritage Trees
4 verified rules • Grass Height Limits, Tree Removal & Heritage Trees
5 verified rules • Grass Height Limits, Tree Removal & Heritage Trees
5 verified rules • Grass Height Limits, Tree Removal & Heritage Trees
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