Posted by Councillor Cindy Gilroy | May 22, 2025
In 2017, Winnipeg faced a sobering moment when the Emerald Ash Borer (EAB) was discovered within city limits. Our City Forester, Martha Barwinsky, recalled the day a resident reported an unusual-looking tree marked by heavy woodpecker activity. After a closer look, the tree was confirmed to be infested with EAB—an invasive insect that destroys ash trees from the inside out, often with little warning.
That day sparked an emergency response, with experts from the Canadian Food Inspection Agency and the Province quickly joining local teams to assess the threat. Cities across North America have lost tens of thousands of trees to this tiny beetle, and Winnipeg braced for the worst.
But something unexpected happened.
Despite EAB’s presence in our city, its spread has been unusually slow. Since that initial discovery, only around 20 ash trees have been removed due to confirmed infestations. While EAB is still here—as shown by traps set up across the city—its population growth appears to be stalled. According to Barwinsky, Winnipeg’s cold winters may be the reason.
“We are finding that our winters are probably affecting the EAB population,” she explained. “The population just is not able to build as quickly as it has in other regions because of our cold temperatures.”
It is a silver lining in a climate that is often hard to endure, but it comes with a warning. Our winters are changing. The periods of extreme cold are getting shorter, and we know insects can adapt. We cannot assume we will stay ahead of EAB forever.
What the City Is Doing
Winnipeg has a comprehensive ash tree management strategy in place. Crews are proactively removing dead or declining ash trees from boulevards and parks. Healthy public ash trees are being treated with a botanical insecticide to help protect them from infestation.
But that only covers a portion of our urban forest. Of the estimated 350,000 ash trees in Winnipeg, approximately two-thirds are on private property. The city cannot act alone—we need the public’s help.
What You Can Do
If you have ash trees on your property, please inspect them regularly. Look for the following signs:
- Dieback in the upper branches
- D-shaped exit holes in the bark
- Excessive woodpecker activity
- Unusual sprouting of branches along the trunk
If you see any of these signs, contact a certified arborist. For trees located on public property, you can report issues directly through the City’s Tree Maintenance Request Form.
Why This Matters
Our urban forest is vital. Trees cool our neighbourhoods, filter the air, provide wildlife habitat, and create the shaded green spaces where we gather and play. The ash trees of Winnipeg are part of that story. While the Emerald Ash Borer has already changed the landscape of many North American cities, here in Winnipeg, we have a rare opportunity to slow its impact.
Let’s use this time wisely. Report signs of infestation. Support our forestry teams. And continue to care for the canopy that makes Winnipeg such a livable city.
Thank you to everyone—residents, arborists, and city staff—who are helping us protect Winnipeg’s trees for future generations.
— Cindy
Listen to More: Our City, Our Podcast
City Forester Martha Barwinsky shares insights on the importance of Winnipeg’s urban tree canopy, how her team is managing threats like Emerald Ash Borer, and practical tips for planting and caring for trees on your own property.
Tune into the May 2025 episode of Our City, Our Podcast to hear the full conversation.
