Tree Ordinance
A tree ordinance is a local law that sets a community’s official policy for how its trees are planted, cared for and protected. NC State Extension says ordinances set standards for selecting, planting, maintaining and conserving community trees, and Illinois DNR says that at a minimum an ordinance identifies who has authority over trees and which tree care standards the community follows.
Sources: Developing Successful Tree Ordinances, NC State Extension ; Tree Care Ordinances, Illinois Department of Natural Resources
Types of tree ordinances
NC State Extension describes several kinds. A street tree ordinance covers planting, maintenance and removal of trees in the rights-of-way, and may also deal with private trees that affect the public interest or pose a public hazard. A tree protection ordinance protects desirable trees, canopy or historic trees on public and private property; some make owners get a permit before removing, pruning or encroaching on a protected tree. Landscape ordinances set required planting, such as the number, placement and types of trees, and buffer ordinances protect views and water quality.
Illinois DNR also describes view ordinances, which help settle disputes between property owners when trees block views or sunlight, and storm water management ordinances.
Sources: Developing Successful Tree Ordinances ; Tree Care Ordinances
What goes into one
NC State lists typical sections: the community’s authority to adopt the ordinance, its purpose and intent, definitions of key terms such as drip line and critical root zone, administrative responsibilities, a tree board, which trees the ordinance applies to, provisions for permits, protection during construction, removal, replanting and mitigation, penalties and appeals, and periodic evaluation of how well it works.
For technical detail, it suggests a short performance standard pointing to a manual that is kept up to date, such as ANSI A300, rather than writing excessive detail into the ordinance, so the ordinance does not go out of date. It also warns that vague phrases such as “minimal disturbance” could make a standard unenforceable or unable to withstand a court challenge.
Mitigation and enforcement
When protected trees come down, many ordinances require mitigation. The Arbor Day Foundation says the amount owed is often tied to the diameter of the trees removed, for example one inch of replacement for each inch lost. Requirements also frequently follow a priority order: replant first on the site itself, next at an approved location elsewhere, and, as the last resort, pay a fee in lieu of planting, typically into a government-run fund for planting trees.
Communities make ordinances stick through enforcement and penalties. NC State calls consistent enforcement the most successful way to get compliance, built on reviewing site and tree protection plans and on inspections at the site, since a developer’s paper plan has to be checked against what is actually happening on the ground.
Sources: Tree Care Ordinance: Mitigation ; Developing Successful Tree Ordinances
How the ISA arborist exam tests it
Ordinance questions in the Urban Forestry domain cover the types of ordinance, permits for work around protected trees, where a town’s authority comes from, how to keep technical standards current, and how to make sure developers comply. Try 5 reviewed practice questions:
Which type of tree ordinance mainly covers the planting, maintenance, and removal of trees in public rights-of-way?
Show answer and explanation
Correct answer: B. Street tree ordinance
A street tree ordinance governs trees in public rights-of-way: how they are planted, maintained, and removed, and sometimes how private trees that endanger the public are handled. A tree protection ordinance, the most tempting alternative, instead protects designated trees or canopy, often on private land, usually by requiring a permit before removal. View ordinances settle disputes over blocked views or sunlight, and landscape ordinances set planting requirements for development.
- A: Tree protection ordinances protect designated trees or canopy, often on private land, through permits.
- C: View ordinances resolve conflicts when trees block views or sunlight.
- D: Landscape ordinances set required plantings, such as trees in parking lots, for development.
Sources: Developing Successful Tree Ordinances, NC State Extension ; Tree Care Ordinances, Illinois Department of Natural Resources
Report a problem with this question · ID urb-015
A builder plans to pave a driveway over part of the root zone of a large oak that the city's tree protection ordinance lists as protected. The oak itself will not be cut down. Which statement reflects how such ordinances commonly work?
Show answer and explanation
Correct answer: B. A permit may be needed, since encroachment and pruning can be regulated too
NC State Extension notes that under some tree protection ordinances, a permit is needed before anyone removes, prunes, or encroaches on a protected tree, and Illinois DNR describes the same pattern. Paving over part of a protected tree's root zone is encroachment, so the builder should check the ordinance before work starts even though the tree will stay. Rules limited to rights-of-way describe street tree ordinances, while protection ordinances can cover trees on public and private property.
- A: Many protection ordinances regulate encroachment and pruning as well as removal.
- C: Local protection ordinances commonly regulate work near protected trees through local permits.
- D: Protection ordinances can cover trees on public and private property, not only street trees.
Sources: Developing Successful Tree Ordinances, NC State Extension ; Tree Care Ordinances, Illinois Department of Natural Resources
Report a problem with this question · ID urb-045
A town in a state that follows Dillon's Rule wants to adopt an ordinance protecting large trees on private land. According to the Arbor Day Foundation's tree ordinance guidance, what must the town's ordinance do?
Show answer and explanation
Correct answer: D. Stay within the authority granted by state enabling legislation
The Arbor Day Foundation explains that Dillon's Rule confines municipalities to the powers a state expressly grants them, so a tree ordinance in such a state must follow state-enabling legislation, while Home Rule states allow broader local authority. NC State Extension likewise notes that local governments may need legal authorization from the state to create tree protection regulations. Dillon's Rule does not ban local tree ordinances outright, and neither federal approval nor copying sample language is required; the Foundation recommends working with the community's legal counsel.
- A: Sample language is a starting point; the ordinance must fit state law, ideally with legal counsel's help.
- B: Dillon's Rule limits local powers to those the state grants; it does not ban tree ordinances.
- C: Authority for local ordinances comes from the state, not from federal approval.
Sources: Tree Care Ordinance: Mitigation, Arbor Day Foundation ; Developing Successful Tree Ordinances, NC State Extension
Report a problem with this question · ID urb-046
A tree board drafting an ordinance wants its pruning and tree care standards to stay current as industry practices are revised. What does NC State Extension recommend?
Show answer and explanation
Correct answer: A. Adopt a basic performance standard that points to ANSI A300
NC State Extension advises keeping ordinance standards basic and, where technical detail is needed, referring to a regularly updated technical standard such as ANSI A300, which keeps the ordinance from going out of date. Writing every specification into the ordinance itself, the tempting choice, makes the text overly detailed and quickly outdated. Undefined phrases like 'minimal disturbance' may not be enforceable and could fail to withstand a legal challenge.
- B: Excessive technical detail in the ordinance itself goes out of date as standards change.
- C: Vague terms left undefined risk being unenforceable and may not stand up to a legal challenge.
- D: Leaving standards out gives the community no enforceable basis for quality tree care.
Sources: Developing Successful Tree Ordinances, NC State Extension ; Developing Successful Tree Ordinances, NC State Extension
Report a problem with this question · ID urb-017
In one city, developers routinely submit tree protection plans that are not followed on site. What does NC State Extension identify as the most successful method of ensuring compliance with a tree ordinance?
Show answer and explanation
Correct answer: A. Consistent enforcement, including field checks of submitted plans
NC State Extension calls consistent enforcement the most successful way to ensure compliance, says the plans developers submit must be checked in the field, and lists on-site inspections as a key element of enforcement. Accepting plans on paper skips that verification, which is the very problem in this city. The publication gives the tree board roles such as reviewing the ordinance, community education and Arbor Day planning, and says the ordinance should name the position responsible for enforcement, such as an urban forester, city arborist or inspector.
- B: Plans must be verified in the field; paper review alone does not ensure compliance.
- C: Waiving requirements weakens protection rather than improving compliance.
- D: The ordinance should name a staff position, such as an urban forester or inspector, to enforce it.
Sources: Developing Successful Tree Ordinances, NC State Extension ; Developing Successful Tree Ordinances, NC State Extension
Report a problem with this question · ID urb-047
0 of 5 correct
Common mistakes in the field
Assuming only removal needs a permit
Under many tree protection ordinances, pruning a protected tree, or encroaching on it, can also need a permit. Illinois DNR says these ordinances usually set a permit requirement that covers removal, pruning and encroachment, so check the local ordinance before the work starts.
Copying another town’s ordinance
NC State recommends reviewing ordinances from comparable communities, but warns that one size does not fit all: the ordinance needs a management strategy suited to the community’s own conditions and goals.
Leaving developers out of the process
NC State says an ordinance cannot be carried out without the input and backing of the development community (commercial developers, including homebuilders, realtors and general contractors), and that talking with them early is most useful. It adds that balance comes from all stakeholders working together so that the result is acceptable and workable.
Looking for a single tree ordinance
Tree rules are often spread across several codes. The Washington State Department of Natural Resources notes that a community’s tree regulations are commonly scattered through various local codes and standards instead of sitting in one tree ordinance, and NC State says tree protection rules other than street tree ordinances are usually written into other ordinances, such as zoning or unified development ordinances.
Sources
- Developing Successful Tree Ordinances, NC State Extension
- Tree Care Ordinances, Illinois Department of Natural Resources
- Tree Care Ordinance: Mitigation, Arbor Day Foundation
- Urban & Community Forestry: A Guide for Local Governments in Washington, Washington State Department of Natural Resources
Written in our own words from the public sources above, checked October 19, 2026. Arborist Practice Test is not affiliated with ISA.