Keeping the Forest City Powered: Why Tree Trimming Matters

Published Date
Tuesday, July 15, 2025
London Hydro Employee trimming tree near power line

London is known as the Forest City for good reason. With thousands of mature trees throughout our neighbourhoods, they play an important role in the character and quality of life in our community. Trees make London greener, healthier, and more livable. But as trees age, they can become vulnerable, particularly during extreme weather like storms and heat waves.

Storms and prolonged heat can stress trees, making their branches weaker over time and increasing the risk of limbs falling onto overhead power lines. That’s why proactive tree maintenance is an essential part of what we do at London Hydro.

Why We Trim Trees

Tree trimming is an important element in keeping your electricity safe and reliable. When branches get too close to power lines, they can cause:

  • Power outages
  • Electrical hazards
  • Damage to homes, property, or utility equipment

We follow strict safety standards and work year-round to maintain safe distances between trees and our primary distribution lines.

How It Works

Our certified Utility Arborists trim trees in dense areas throughout the city on a three-year cycle, balancing safety and tree health. We plan our work to minimize disruption and leave the area clean and safe afterward. We also handle emergency tree trimming after major storms and, as needed, during planned project work.

When it comes to pruning, we consider the type of tree and how fast it grows. Fast-growing trees are trimmed back more than slow growers, so that safety clearances are maintained longer between visits.

Who’s Responsible for What?

London Hydro is responsible for trimming trees around primary power lines. These are the main lines that run along streets and through neighbourhoods. If a tree or branch is within three meters of these lines, it’s our job to manage it.

However, the service line that runs from a pole to your home is your responsibility. If vegetation is encroaching there, you’ll need to hire a qualified contractor. We can schedule a temporary outage so that the work can be done safely.

The City of London handles tree trimming around street lights.

Heat and Tree Health

Many people don’t realize that extreme heat doesn’t just affect people and buildings. It also impacts trees. Prolonged hot weather can stress and weaken trees, particularly older ones, making them more likely to shed limbs. That’s why regular, proactive trimming is important. Well-maintained trees are stronger and more resilient year-round.

Planting Smart

If you’re thinking about planting a tree near your home, be sure to consider its mature height. Trees that will grow taller than 6 meters (20 feet) should be planted well away from power lines. For smaller trees, maintain at least 4.5 meters (15 feet) of space from either side of the line. Never plant closer than 1.5 meters (5 feet) to the base of a hydro pole.

Safety First

If you ever see a tree limb touching or near a power line, or worse, a downed wire, stay at least 10 meters (33 feet) away. Call 911 in the case of an emergency and then contact London Hydro at 519-661-5555.

Questions?

We’re always here to help. If you have any questions or concerns, please visit our website at www.londonhydro.com/contact-us.