Landscaping Rules in Hillsboro, OR: What Residents Actually Need to Know

If you live in Hillsboro or are thinking about moving there, landscaping rules are one of those things you probably won't think about until they affect you directly. Hillsboro has 4 specific rules on the books covering different aspects of landscaping rules, and some of them might surprise you.

Water Restrictions

Hillsboro has no standing lawn-watering schedule; non-voluntary water curtailment activates only after the City Manager declares an emergency under HMC 2.60, with escalating fines then service shutoff for violators.

Key details: Citation: HMC § 10.04.040. Trigger: Emergency declared under HMC 2.60. 1st fine: After 1 warning, 1 notice. 3rd violation: Fine plus service shutoff. Appeal window: 10 days to City Recorder.

A first curtailment violation draws a warning, then a fine under HMC 1.08.010; a third violation triggers both a fine and termination of water service until fines are paid and a no-repeat agreement is signed.

Tree Removal & Heritage Trees

Removing a mature tree, 8+ inches in diameter or a 30-foot conifer, during a Type II or Type III development application in Hillsboro requires City review, an arborist's preservation plan, and proof the removal is necessary.

Key details: Trigger: Type II/III development applications only. Mature tree: 8-in deciduous or 30-ft conifer. Arborist plan: Required for 5+ overlapping canopies. Protection fencing: 5 feet outside tree drip line. Enforcement: Stop Work order for violations.

Site or building construction that violates the tree preservation standards, intentionally or through negligence, can draw a City Stop Work order under CDC § 12.50.230.C.7, halting the project until a binding mitigation agreement is signed.

This is not one of those rules that cities tend to ignore. Hillsboro actively enforces its tree removal & heritage trees requirements.

Weed Ordinances

Hillsboro caps grass and weeds at 12 inches on every lot in the city. The Municipal Code defines anything taller as "noxious vegetation," which is automatically a public nuisance. The City Manager can order it cleared on 15 days' notice, or summarily abate it without advance notice if it poses an imminent hazard, then bill the owner.

Key details: Height trigger: Grass/weeds over 12 inches. Legal status: Automatically a "nuisance". Notice period: Up to 15 days to abate. Emergency power: Summary abatement, no advance notice. Unpaid cost result: Becomes a property lien in 30 days.

Each day the noxious vegetation remains is a separate offense under HMC 6.28.010(C). Abatement costs the City incurs, including administrative costs, must be paid by the owner within 30 days of a summary abatement or the amount becomes an assessment lien on the property (HMC 6.28.030(B)). The City can also sue in any court of competent jurisdiction and recover its reasonable attorney and expert fees under HMC 6.28.050, on top of any civil penalties imposed through the municipal court action.

Tree Trimming

Hillsboro property owners must keep limbs, bushes and other vegetation clear of the street and sidewalk in front of their property: a minimum 8 feet above the sidewalk and 15 feet above the roadway, per Hillsboro Municipal Code § 6.16.020(B). Vegetation that blocks a driver's view, blocks pedestrians or bikers, or grows onto the right-of-way as noxious growth is a code violation, and the owner is liable for resulting injuries and the city's abatement costs.

Key details: Sidewalk clearance: 8 feet minimum overhang height. Roadway clearance: 15 feet minimum overhang height. Who may trim public ROW: City employees or contractors only, unless HMC 9.18 assigns owner duty. Penalty: $500 fine, separate offense per day. Civil liability: Owner liable for injuries and city's legal costs.

Failing to keep the required 8-foot sidewalk and 15-foot roadway clearance, or letting noxious growth spread onto the right-of-way, is a Municipal Code violation carrying the City's standard $500.00 penalty under HMC 1.08.010(B), and every day the obstruction continues is a separate offense under HMC 1.08.030. Beyond the fine, HMC 6.16.020(E) makes the property owner personally liable for injuries the overgrowth causes and for the City's costs, expenses and attorney fees in any resulting claim or judgment.

The Bottom Line

Hillsboro's landscaping rules rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Hillsboro is broadly strict or permissive.

This guide is based on Hillsboro's current municipal code. Local rules can and do change, so check the individual ordinance pages for the latest details, penalties, and FAQs.