Landscaping Rules in Nashua, NH: What Residents Actually Need to Know

If you live in Nashua or are thinking about moving there, landscaping rules are one of those things you probably won't think about until they affect you directly. Nashua has 8 specific rules on the books covering different aspects of landscaping rules, and some of them might surprise you.

Weed Ordinances

Nashua does not publish a separate prohibited-species list in its Revised Ordinances (ecode360 NA2698). Overgrown weeds and noxious vegetation are abated under the City's general nuisance authority enforced by Code Enforcement (Building Safety Department). New Hampshire's statewide prohibited invasive plant list is administered by the NH Department of Agriculture, Markets & Food under RSA 430:53 and Agr 3800, which makes it unlawful to collect, transport, import, export, move, buy, sell, distribute, propagate, or transplant any listed prohibited invasive plant species.

Key details: Local Authority: Nashua Code Enforcement — Building Safety Department. Local Prohibited-Species List: None published. State Authority: NH RSA 430:53 / Agr 3800 Invasive Species Rule. State Enforcement: NH Department of Agriculture, Markets & Food. Site-Plan Plants: Article XXVII — hardy for Nashua botanical zone.

Local nuisance violations are abated under written notice; failure to comply allows the City to abate at the owner's cost. Statewide invasive-species violations are enforced by the NH Department of Agriculture, Markets & Food under RSA 430:53; civil penalties may be assessed for selling, distributing, or planting prohibited species. Site-plan landscape-material failures are referred to Nashua Planning and Building Safety.

Grass Height Limits

Nashua does not set a fixed inch-height standard for residential grass in its Revised Ordinances (ecode360 NA2698). Overgrown grass, weeds, and other vegetation are addressed through the City's nuisance-abatement framework administered by Code Enforcement (Building Safety Department) and through the landscape-maintenance provisions of Chapter 190 Article XXVII for sites subject to an approved landscape plan. Site landscape material that is required as part of an approved site plan must be maintained in a healthy, growing condition and replaced when necessary.

Key details: Local Authority: Nashua Code Enforcement — Building Safety Department. Fixed Inch Height: None — operates under nuisance / property maintenance standard. Site-Plan Landscapes: Article XXVII (Ch. 190) — maintenance + replacement required. State Authority: NH RSA 47:17 — city nuisance abatement. Reporting: Code Enforcement at 603-589-3216.

Nuisance vegetation is enforced under Nashua's nuisance abatement authority. The City may issue a written notice to abate; if the owner fails to cure within the stated period, the City may abate at the owner's cost and assess the cost against the property. Continued non-compliance may be referred to Nashua District Court. Site-plan landscape maintenance failures under Article XXVII are referred to the Planning Department and Building Safety for replanting orders and enforcement.

Tree Trimming

The Nashua Board of Public Works has cognizance, direction and full control of the planting and care of trees standing in the streets and public ways. Routine pruning of healthy trees on private property is not subject to a Nashua permit. Trees within the public right-of-way, on parks, or other public land are maintained by the City; residents must obtain Board of Public Works authorization before pruning, removing, or otherwise altering a street tree or other public tree. Eversource and other utilities prune for line clearance under their easements.

Key details: Public ROW Authority: Nashua Board of Public Works. Private Pruning Permit: Not required on private lots. Common Law: Massachusetts Rule — trim to property line, no trespass / no kill. State Tree Warden Law: NH RSA 231:139 (not RSA 232). Public Tree Damage: NH RSA 231:158 — penalty for intentional injury.

Unauthorized cutting, pruning, or damage to a tree in a Nashua street or public way may be enforced as damage to public property under City code. NH RSA 231:158 imposes a fine for intentional damage to public shade or ornamental trees without consent. Trespass and tree damage on a neighbor's land exposes the cutter to civil damages under NH RSA 539:1 — the statute allows up to ten times the value of the tree for willful and knowing damage and treble the value if done through carelessness.

Rainwater Harvesting

Rainwater harvesting is legal in Nashua. New Hampshire has no statute prohibiting residential rain barrels, cisterns, or roof-runoff capture, and NH DES actively promotes rain-barrel use through its Soak Up the Rain New Hampshire program. Nashua does not impose a permit on a simple downspout-fed rain barrel. Plumbed cisterns connected to building plumbing — particularly for indoor non-potable reuse — require permits from the Nashua Building Safety Department and must comply with the NH State Building Code (IPC Chapter 13 / Appendix C) and NH DES rules for backflow prevention on any cross-connection with the Pennichuck public water supply.

Key details: Rain Barrels (Outdoor): Legal — no Nashua permit required. Plumbed Cisterns (Indoor): Plumbing permit required — Nashua Building Safety. Design Code: NH State Building Code / IPC Ch. 13 (Appendix C). State Promotion: NH DES Soak Up the Rain (SOAK-NH) program. Backflow Prevention: Required on any potable cross-connection (Pennichuck).

There is no Nashua penalty for installing a rain barrel for outdoor garden irrigation. Plumbing a cistern into building plumbing without the required permit is a NH State Building Code / NH Plumbing Code violation enforced by the Nashua Building Safety Department with stop-work and after-the-fact permitting. Cross-connections that contaminate the Pennichuck public water supply trigger NH DES Public Water Supply enforcement and immediate utility action.

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

Native Plants

Nashua does not mandate native plants in private landscapes. Chapter 190 Article XXVII Landscaping requires that all shade trees in required landscape material be hardy for the Nashua botanical zone and encourages inclusion of existing trees in the landscape design. Public outreach through the Nashua Conservation Commission and NH DES Soak Up the Rain program promotes native and pollinator-friendly plantings, particularly in wetland buffers and the Nashua River and Merrimack River corridors. New Hampshire has no statewide HOA xeriscape protection statute.

Key details: Mandatory Native Use: None — natives encouraged, not required. Article XXVII Standard: Trees hardy for Nashua botanical zone; 2½ in caliper / 6 ft evergreen. Mix Requirement: ≤60% deciduous, ≥40% evergreen in required landscape. Conservation Outreach: Nashua Conservation Commission + NH DES SOAK-NH. Prohibited Species: NH Agr 3800 invasive-plant list.

There is no Nashua penalty for choosing non-native ornamentals on a private lot. Failure to maintain required landscape material under Article XXVII (including dead/dying replacement) is enforced by the Planning Department and Building Safety. Planting or distributing a prohibited invasive species violates NH RSA 430:53 / Agr 3800 and is enforced by NH Department of Agriculture, Markets & Food. HOA design-review enforcement is a private contract matter handled in Hillsborough County Superior Court.

Nashua is more permissive than most cities when it comes to native plants. That said, there are still limits.

Water Restrictions

Nashua is served by Pennichuck Water Works (Pennichuck Corporation), a publicly owned utility under the Pennichuck East Utility / Pennichuck Water umbrella. Pennichuck enforces a four-level water restriction schedule that operates year-round: Level 1 odd/even house-number lawn watering; Level 2 two assigned days per week between 5:00 a.m. and 8:00 a.m.; Level 3 one assigned day per week between 5:00 a.m. and 8:00 a.m.; Level 4 total outdoor water ban. Hand-held hoses and watering cans are permitted for vegetable and flower gardens any day. Small kiddie pools (6 feet or less in diameter, 12 inches deep or less) may be filled any day.

Key details: Water Provider: Pennichuck Water Works (Pennichuck Corporation — publicly owned). Schedule Authority: Pennichuck Water Restriction Levels 1-4 (year-round). Level 1: Odd/even house-number lawn watering. Level 2: Two assigned days/week, 5:00-8:00 a.m. only. Level 3: One assigned day/week, 5:00-8:00 a.m. only.

Pennichuck Water Works states: 'First time violators will receive a written warning for non-compliance and further instances that violation outside usage restrictions will result in disconnection of service. A fee for re-connection will be charged.' Reconnection requests received before 6:00 p.m. on the day of disconnection are reconnected the same day; otherwise reconnection occurs the next business day after 7:30 a.m. Restrictions are enforced by Pennichuck rather than by City code enforcement.

Compared to other cities, Nashua takes a harder line on water restrictions. The enforcement and penalty structure reflects that.

Tree Removal & Heritage Trees

Tree removal on private residential property in Nashua is generally not subject to a City removal permit, except where the tree is in a designated wetland or wetland buffer (Article XI of Chapter 190), within required landscape material under Article XXVII, designated for retention on an approved site plan, or in a regulated conservation area. The Board of Public Works has full control over the removal of any tree standing in a Nashua street or public way. NH RSA 231:145 governs the declaration and removal of public-highway trees deemed nuisances.

Key details: Routine Private Lots: No general City permit required. Wetlands/Buffer Trigger: Article XI Ch. 190 — buffers 20-75 ft (100 ft vernal pool). Site-Plan Trigger: Article XXVII required landscape material. Public Trees: Board of Public Works approval required. State Wetlands: NH DES Wetlands Permit under RSA 482-A.

Unauthorized removal of a tree subject to Article XI (wetlands), Article XXVII (required landscape material), or a retention condition is a Chapter 190 violation enforced by the Planning Department and Code Enforcement with civil penalties and replacement obligations. Unauthorized removal of a tree in the Nashua public way is enforceable as damage to public property and under NH RSA 231:158. Wetland buffer work without DES approval is enforced by NH DES under RSA 482-A.

Artificial Turf

The Nashua Revised Ordinances do not contain a code provision specifically prohibiting or permitting artificial turf in residential or commercial landscapes. Where landscape material is required under Chapter 190 Article XXVII, the standards reference living plant material — trees, shrubs, and ground cover — so synthetic turf cannot substitute for required landscape area on a site-plan-approved development. On private single-family residential lots, artificial turf is permitted, but installations with impermeable backing may count as impervious surface for stormwater and wetland-buffer calculations under Article XI and the City's NPDES MS4 stormwater rules.

Key details: Specific Ordinance: None — generally permitted on private SF lots. Site-Plan Landscapes: Article XXVII requires living plant material. Wetland Buffers: Impermeable turf may count as impervious — Article XI. Stormwater: MS4 post-construction rules treat impermeable backing as impervious. Water Rebate: None from Pennichuck Water Works.

There is no specific Nashua fine for installing artificial turf on a private single-family lot. Substituting artificial turf for required Article XXVII landscape material is a Chapter 190 violation enforced by Planning and Code Enforcement with replanting orders and civil penalties. Impervious-surface violations in a wetland buffer trigger Conservation Commission enforcement under Article XI and NH DES action under RSA 482-A. HOA architectural-review disputes are private contract matters in Hillsborough County Superior Court.

If you are coming from a city with tighter rules, you will find Nashua gives residents more flexibility on artificial turf.

The Bottom Line

Compared to many U.S. cities, Nashua gives residents more room on landscaping rules. 3 of the 8 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 Nashua's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.