Assessment Results

Tree Planting

Specifications for the planting of trees, including standards for tree size, species, soil volume, spacing, and other criteria. 

Before reviewing your results, verify how your state governs local authority. States follow either Dillon’s Rule, which limits municipalities to powers explicitly granted by the state, or Home Rule, which allows broader local authority unless specifically prohibited by state law. If you’re in a Dillon’s Rule state, your tree ordinance must follow state-enabling legislation. Check your state statutes, municipal league, or community forestry program to confirm your state’s model.

When developing or revising a tree ordinance, we recommend you work with your community’s legal counsel. Legal counsel will help ensure your ordinance complies with state and local requirements, properly establishes enforcement authority, and can achieve your community's goals, while avoiding potential legal challenges.

Introduction

Tree planting standards provide quality control for new plantings. They help ensure the “right trees” are planted in the “right places”, which improves the health and longevity of the urban forest. Tree planting standards should include these key aspects:  

  • Approved and/or Prohibited species lists: A list of tree species that are well-suited for the local climate, often categorized further into trees for street plantings vs park/yard trees. A list of trees not suitable or desirable for planting in a community. 

  • Tree size: Minimum caliper, gallon, or height requirements for new plantings (i.e. deciduous trees must be at least 2-inch caliper and evergreen trees must be at least 6ft tall). 

  • Spacing minimums: Requirements to prevent overcrowding, promote healthy growth, and maintain safe distances from utilities or other infrastructure conflicts. 

  • New development: Standards for how many new trees a development must plant, often dependent on the lot/building size, street frontage, zoning type, and/or existing tree cover on site. For example, 3 trees are required per single family lot or 1 shade tree per 10 parking lot spaces.  

 

The three levels below show how these aspects can range in complexity, depending on the goals and resources of your community. 

Key Definitions

Approved Species List

A municipally curated list of trees suitable for planting based on climate, soil, pest resistance, and canopy goals.

Caliper Size

Trunk diameter measured 6" above ground for trees <4" DBH, or at breast height (4.5') for larger trees.

Planting Specifications

Requirements for depth, spacing, mulch, and irrigation, per ANSI A300 (Clause 6) standards.

Example Language

Basic

Basic Level

Basic ordinances list approved species for planting but may not specify minimum size, spacing, or soil requirements. This encourages the use of appropriate trees and supports basic urban forestry goals. 

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Basic

Planting Specifications 

  1. Tree Quality and Size  

    1. All trees planted must be healthy, typical of their species, and free from pests and disease.  

    2. At the time of planting, canopy trees shall have a minimum trunk diameter of two inches measured four and one-half feet above grade and a minimum height of eight feet. 

  1. Planting Location.  

    1. Trees must be planted in locations that do not interfere with utilities or obstruct visibility at intersections.  

    2. No tree may be planted within 10 feet of utility lines or within the visibility triangle of a street intersection. 

  1. Planting Practices.  

    1. Trees must be planted according to sound nursery practices, with the root flare at the soil surface and the root ball resting on a bed of topsoil at least six inches deep.  

    2. Mulch must be applied to a minimum depth of three inches around the base of each tree. 

Examples

Granville, Ohio

Granville, OH Code of Ordinances. Chapter 1184 - Tree Preservation Code, Sec. 1184.11. Accessed May 29th, 2025. 

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Canton, Ohio

Canton, OH Code of Ordinances. Chapter 917 - Trees, Sec. 917.07. Accessed May 29th, 2025. 

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Brevard, North Carolina

Brevard, NC Code of Ordinances. Chapter 8 - Tree Protection and Landscaping, Sec. 8.5. Accessed May 29th, 2025. 

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Intermediate Level

Intermediate ordinances set standards for caliper size, spacing, soil volume, and distance from utilities, improving tree establishment and longevity. These requirements help ensure new plantings thrive and fit the site context. 

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Intermediate

Planting Specifications 

  1. Tree Quality, Size, and Diversity 

    1. All trees must be [insert regional nursery standard] quality or equivalent, free of defects, and typical of their species.  

    2. Canopy trees must be at least 2.5 inches in diameter and eight feet tall at planting. A minimum of two species is required for every 10 trees planted, with additional species required for larger plantings to promote diversity. 

  1. Species Selection and Placement 

    1. Trees must be selected from the City’s approved species list, with preference for native or climate-adapted species.  

    2. Only ornamental trees may be planted under or within 15 feet of overhead utility lines.  

    3. Spacing between trees shall be at least 15 feet for small trees, 25 feet for medium trees, and 35 feet for large trees. 

  1. Planting Methods 

    1. Planting holes must be at least twice the width of the root ball and no deeper than the root ball itself. 

    2. Excess soil must be removed to expose the root flare. 

    3. All ropes, burlap, and wire baskets must be removed from the upper half of the root ball before backfilling. 

    4. Mulch must be applied in a 3-inch layer but kept away from direct contact with the trunk. 

    5. Trees must be staked only if necessary for stability and all staking materials must be removed after one year. 

  1. Coordination and Timing. Planting must be coordinated with the City Forester. All balled and burlapped trees must be planted within three days of delivery to the site. 

Examples

La Crosse, Wisconsin

La Crosse, WI Code of Ordinances. Chapter 34 - Parks, Recreation, Boulevards, and Other Public Places, Sec. 34-144. Accessed May 29th, 2025. 

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Germantown, Tennessee New Development

Germantown, TN Code of Ordinances. Chapter 22 - Vegetation, Sec. 22-107. Accessed May 29th, 2025. 

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Port Arthur, Texas

Port Arthur, TX Code of Ordinances. Appendix A - Zoning, Sec. 4.02.F. Accessed May 29th, 2025. 

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Advanced Level

Advanced ordinances require engineered soil systems, irrigation plans, and species diversity quotas, maximizing ecosystem services and resilience to pests or climate change. 

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Advanced

Planting Specifications 

  1. Tree Quality, Size, and Biodiversity 

    1. All trees shall be specimen-quality, free of disease and defects, and sourced from nurseries following best management practices.  

    2. Trees must be at least 2 inches in diameter and 10 feet tall at planting.  

    3. Plantings must include at least four species for every 30 or more trees, and no single species may comprise more than 20% of the total. 

  1. Species Selection, Placement, and Site Suitability 

    1. Trees must be selected from the City’s Master Street Tree List, prioritizing native, climate-resilient, and pollinator-supporting species. 

    2. Species must be compatible with site soil, drainage, and microclimate conditions. 

    3. Trees with mature heights exceeding 25 feet may not be planted within 20 feet of overhead power lines unless specifically approved. 

    4. Root barriers are required when planting within 10 feet of hardscape to protect infrastructure. 

  1. Planting Methods and Soil Preparation 

    1. Planting holes must be at least twice the width of the root ball and no deeper than the root ball itself. 

    2. Soil amendments and mycorrhizal inoculants are encouraged where appropriate. 

    3. All trees must be mulched with 3 inches of organic mulch, kept 3 inches away from the trunk. 

    4. Irrigation must be provided for at least two years after planting, either through permanent systems or scheduled hand watering. 

  1. Installation, Maintenance, and Documentation 

    1. All planting must be performed by or under the supervision of a certified arborist. 

    2. A planting plan showing species, locations, and spacing must be submitted and approved prior to installation. 

    3. The property owner is responsible for maintenance and replacement of any tree that dies within three years of planting. 

    4. Annual survival reports must be submitted to the city for three years following installation. 

Examples

Ogden, Utah

Ogden, UT Administrative Manual. Title 10 - Public Services, Sec. 1900-4. Accessed May 29th, 2025. 

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Tillamook, Oregon

Tillamook, OR Code of Ordinances. Chapter 93 - Trees, Sec. 93.05. Accessed May 29th, 2025. 

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Livonia, Michigan

Livonia, MI Zoning Ordinance. Article X - Landscaping and Screening, Sec.10.03. Accessed May 29th, 2025. 

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Relevant Industry Standards and Best Management Practices

ANSI A300 Clause 10 Planting and Transplanting (2023): Specifies standards for planting depth, root ball sizing, transplanting methods (e.g., balled-and-burlapped, bare-root), and post-planting care. Emphasizes locating the trunk flare at grade to avoid deep planting.