Tree guides
Pruning can still be regulated.
Branch removal, root cutting and grade changes can count as tree injury. Public-tree work has its own permission rules.
Removal is not the only trigger
Check local rules before topping, major crown reduction, root cutting, excavation or work on a City tree.
The citywide permit portal identifies major intervention triggers including cutting 40% or more of a tree’s branches or 40% or more of its roots, with borough-specific rules that can differ.
Toronto’s bylaw regulates both injury and removal of protected trees. A permit can be required for work that injures a protected private tree, City tree or tree/ravine feature.
Ottawa’s Tree Protection By-law covers injury or destruction of protected trees and requires protection measures for retained trees where work could affect them.
For City-owned trees, cutting, removing, moving or pruning is prohibited without City permission. Calgary also prohibits unauthorized interference with a public-tree protection zone.
Root work counts
- Driveways, drainage, retaining walls, trenches and grade changes can cut or compact roots.
- Montréal identifies major root cuts and raising soil beneath the canopy as permit triggers.
- Toronto and Ottawa also regulate construction injury around protected trees.
Before major pruning
- Confirm ownership. Never assume a boulevard or street tree belongs to you.
- Check whether the tree is protected by size, location or development condition.
- Define the proposed pruning as a percentage or scope, not just “trim.”
- Ask whether roots or grade will also be affected.
- Use a qualified arborist where the work could affect structure or long-term health.
Maintenance or injury?
Normal maintenance may be allowed. Excessive pruning, topping or disturbance to protected roots may be restricted. Check the local line before substantial work that changes a tree’s structure or live crown.
Official sources
Sources were re-checked for this guide on September 29, 2026. Municipal bylaws, fees, exemptions and development conditions can change. Use the linked municipality for the current rule before work begins.
Independent information, not legal or arboricultural advice. Ownership, site conditions and professional assessments can change the answer.