Halifax is considering a new plan to protect hemlock trees on municipal land from an invasive insect spreading across the province.
The hemlock woolly adelgid has been killing hemlocks in Nova Scotia since at least 2017 but was only detected in Halifax Regional Municipality in 2023.
On Thursday, municipal staff presented a treatment and management plan for the woolly adelgid to the city’s environment and sustainability standing committee. The plan was created over the past year with input from parks and urban forestry staff, experts and the public.
Hemlocks in certain areas would be injected with a chemical insecticide that maintains its efficacy for about five years. The program would be carried out by contractors, municipal staff and volunteers.
“I’ve got some amazing memories of not only hiking but camping in some of our hemlock forests in Nova Scotia,” said Deputy Mayor Tony Mancini, committee chair. “To hear that they’re threatened is emotional, and we all have a role to play.”
Mancini said he doesn’t anticipate any difficulty attracting volunteers because he’s seen many examples of Haligonians stepping up to help preserve the local environment. As an example, he cited the success of the LakeWatchers program in which residents collect water quality data.
It is estimated that the insect can kill up to 95 per cent of hemlocks in an area within as little as three years, the plan said, while some stands are completely destroyed.
“There are increased fire risks as these standing dead trees dry out … Sometimes you’ll see increased flooding and erosion in areas where the hemlocks are dying,” said Shauna Doll, environmental specialist with Halifax’s environment and climate change team.
“So it’s not just the fact that we’re losing these trees, it’s that there’s a lot of knock-down effects that are going to be seen as a result of these trees declining.”
The plan said 15 municipal parks with a total of 50 hectares of hemlocks will be treated first, covering most of the 70 hectares of hemlock found in parks within the municipality.
Doll said the sites were prioritized based on provincial data and public feedback.
Bedford’s Sandy Lake Park — with about 36 hectares of hemlock — is first on the list, partly because the woolly adelgid was already reported in the park in 2024. Treatment would begin this fall.
The plan said the insect was also detected in Bedford’s Hemlock Ravine Park and Shubie Park in Dartmouth, so those parks are also on the list of 15. Because it was found in the Oakfield area near Enfield as well, hemlocks in Sawgrass Drive Park and Oakfield Woods Park will also be treated.
The program would cost $150,000 to $200,000 per year for the five-year treatment cycle, the plan said.
This funding is in place for this fiscal year, but more money will be needed in the 2026-27 budget cycle to continue the program, the plan said. Halifax staff said they are also looking for other funding from private sources, grants or cost-sharing with the province.
The plan said based on provincial data, nearly 350 of HRM’s 900 municipal parks are expected to contain some number of eastern hemlock.
The environment committee passed along the plan to regional council, which will make a final decision at a future meeting.
