Visitors to Sayward Hill Park may have noticed signs warning that pesticides are being applied to trees in the area, but the District of Saanich says there is no need for concern.
Saanich parks staff will be applying a herbicide called Garlon XRT in Sayward Hill Park from Jan. 18 to 29 to control the invasive English holly and hawthorn. As a precaution, park users are advised to avoid handling the treated plants for 24 hours after application.
Eva Riccius, Saanich’s senior manager of parks, said staff use herbicides to “target only a number of priority invasives” – knotweed, shiny geranium, lesser celandine, garlic mustard, gorse and English holly. Invasive species such as blackberries and ivy are pulled by hand while the six select invasive species are treated regionally to prevent them from spreading.
In Sayward Hill Park, small holly plants were pulled by hand while the larger bushes were felled like trees so the stumps could be treated with Garlon to prevent regrowth, Riccius explained. The herbicide is mixed with a mineral oil before being applied directly onto the face of the stumps, she said, adding that the active ingredient in Garlon is triclopyr and has been approved as a best management practice by the regional invasive species committee.
Garlon is not sprayed onto plants or widely used, she said, and it’s only used “as a last resort.”
When Garlon is used, the district is required to post signs indicating where and when the herbicide has been applied and must also file an annual report to the Ministry of Environment and Climate Change Strategy outlining how much has been used and where.
In 2019, the district used 350mL of the Garlon-mineral oil solution on 50 tree stumps in Sayward Hill Park, Riccius said. The solution, about 7 mL per tree, was “globbed directly onto the stump” and the mixture soaks in quickly, she said. No herbicides were applied to holly plants in the park in 2020.
This year, staff treated approximately 45 stumps in the park with 400 mL of the Garlon-mineral oil solution and the smaller plants were pulled by hand.
Anyone with questions or concerns can visit saanich.ca or call the parks department at 250-475-5522.