How Urban Honolulu Handles Landscaping Rules: A Practical Guide

Urban Honolulu maintains 119 local ordinances across all categories, and 9 of those deal specifically with landscaping rules. Here is a breakdown of what the city actually requires, what is prohibited, and where Urban Honolulu falls on the strict-to-permissive spectrum compared to other cities.

Tree Removal & Heritage Trees

Urban Honolulu enforces ROH Chapter 40 Article 8 on exceptional trees that line Manoa, Makiki, and Nuuanu residential streets, blocking removal without a Parks and Recreation permit except under Sec. 40-8.9 emergencies.

Key details: Code sections: ROH 40-8.1 to 40-8.9. Permit agency: Parks and Recreation. Register section: Sec. 40-8.7. Emergency rule: Sec. 40-8.9. Key neighborhoods: Manoa, Makiki, Nuuanu.

Unauthorized removal of an exceptional tree is prosecutable and can carry substantial civil penalties, replacement tree obligations, and restoration assessments.

This is one of the stricter rules in Urban Honolulu's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

Artificial Turf

Urban Honolulu has no specific artificial turf ordinance; LUO Sec. 21-4.70 landscape rules apply citywide, with DPP deciding case-by-case whether turf counts toward required landscape area in dense projects.

Key details: Code section: LUO Sec. 21-4.70. Specific ordinance: None. Residential permit: Not required. Landscape credit: DPP case-by-case. Condo rules: May apply on balconies.

If turf eliminates required landscape area, Planning and Permitting can require corrective planting; no standalone turf penalty exists in the code.

The rules around artificial turf in Urban Honolulu lean permissive, but that does not mean anything goes.

Grass Height Limits

Urban Honolulu regulates overgrown vegetation as a public nuisance under ROH Chapter 16A without a numeric grass height, with dense enforcement pressure in Waikiki, Kakaako, and Ala Moana neighborhoods.

Key details: Code chapter: ROH Chapter 16A. Compliance window: 30-day notice. Enforcement: Planning and Permitting. Height limit: Not numerically specified. Focus areas: Kakaako, Chinatown, Kalihi.

After the 30-day notice expires the city may abate the nuisance and bill the owner; unpaid abatement costs become a lien recorded against the parcel.

Water Restrictions

Urban Honolulu follows ROH Sec. 30-2.3 for water conservation authority, with Board of Water Supply shortage-stage rules hitting high-rise condos in Waikiki and Ala Moana through landscape irrigation limits.

Key details: Code section: ROH Sec. 30-2.3. Shortage rules: Board of Water Supply. Stages: Stages 1 through 4. Urban impact: Condo, hotel, Kakaako. Non-potable irrigation: Allowed.

BWS may issue warnings, fines, and ultimately disconnect service for repeat shortage-rule violations; Chapter 30 noncompliance triggers separate civil penalties.

Tree Trimming

Urban Honolulu requires Department of Parks and Recreation permits under ROH Sec. 10-1.4 for any work on street trees, a frequent issue along Kalakaua Avenue monkeypods and Ala Moana Boulevard shower trees.

Key details: Code section: ROH Sec. 10-1.4. Permit agency: Urban Forestry Division. Dense corridors: Kalakaua, Ala Moana Blvd. Exceptional trees: Chapter 40 Article 8. Applies to: Public right-of-way.

Unpermitted cutting of street trees can result in fines, replacement-tree obligations, and reimbursement of the city's assessed tree valuation.

Weed Ordinances

Urban Honolulu enforces ROH Sec. 16A-2.1 et seq. on vacant lots in Kakaako redevelopment areas, downtown infill parcels, and Iwilei industrial edges, with a 30-day notice before city abatement.

Key details: Code section: ROH Sec. 16A-2.1 et seq.. Notice period: 30 days. Lien eligible: Yes if unpaid. Hotspots: Kakaako, Iwilei, Kapahulu. Trigger: Fire, vermin, obstruction.

Unpaid abatement charges can be recorded as a lien; repeat violations on the same parcel trigger escalating administrative costs and ongoing monitoring.

Rainwater Harvesting

Urban Honolulu has no ordinance restricting rainwater harvesting; Board of Water Supply rebates target rain barrels at single-family homes in Kaimuki, Manoa, and Palolo rather than high-rise condos.

Key details: City ordinance: None. Permit exemption: Up to 360 gallons. Rebate program: Board of Water Supply. Best fit: Single-family neighborhoods. Guidelines: UH CTAHR catchment program.

No specific violations apply to residential harvesting; larger systems or potable-plumbing tie-ins must meet standard building and plumbing code requirements.

If you are coming from a city with tighter rules, you will find Urban Honolulu gives residents more flexibility on rainwater harvesting.

Native Plants

Urban Honolulu allows native Hawaiian species as substitutions under LUO Sec. 21-4.70 but does not require native-only landscaping, with voluntary xeriscape guidance used in Kakaako and downtown streetscapes.

Key details: Code section: LUO Sec. 21-4.70. Native mandate: None. Substitution allowed: Yes. Guidance: BWS Xeriscape Program. Common in: Kakaako streetscapes.

Failure to comply with approved landscape plans under LUO Sec. 21-4.70 can delay certificates of occupancy and trigger correction orders from Planning and Permitting.

If you are coming from a city with tighter rules, you will find Urban Honolulu gives residents more flexibility on native plants.

Composting

Urban Honolulu implements ROH Sec. 42-3.5 food waste recycling, with Ordinance 23-30 rolling out G.R.O.W. curbside collection by April 1, 2025 and mandatory diversion for Waikiki and Ala Moana food establishments.

Key details: Code section: ROH Sec. 42-3.5. Ordinance: Ord. 23-30 (Bill 47). Program: G.R.O.W. curbside. Start date: April 1, 2025. Hotel mandate: Yes in Waikiki.

Commercial generators and haulers that fail to divert can face fines, service suspensions, and enforcement actions by the Department of Environmental Services.

The Bottom Line

Compared to many U.S. cities, Urban Honolulu gives residents more room on landscaping rules. 3 of the 9 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

These rules come from Urban Honolulu's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.