A program to treat invasive plants on both the Upper and Lower Sunshine Coast has been successful, according to a representative from the company working on the project.
The Coastal Invasive Species Committee (CISC) has contracted Capilano Highway Services for the past three seasons to carry out a treatment program. Various agencies contribute funds for the contract, including Powell River Regional District and the ministry of transportation and infrastructure.
Tyler Lambert, manager of roads and projects for Capilano, reported on the program during a recent regional district committee-of-the-whole meeting. He said that Japanese knotweed was almost exclusively treated during the past year. “There are lots of invasive plants out there, but knotweed is the one that’s still contained enough that we might be able to eliminate it here,” he said. “It’s also one of the nastier ones in terms of damage to infrastructure.”
There was an increase in public reporting this year, Lambert said, which he attributed to ongoing public education. “We’ve been doing outreach sessions with the public, both upper and lower coast, trying to get them to understand what the plant is and the use of herbicides,” he said.
Treating Japanese knotweed takes multiple years, sometimes up to five, Lambert explained. “We’re now in year three on some of these sites and we’re able to go back and look at the successes we’ve had,” he said.
Between 40 to 50 sites on ministry of transportation rights-of-way were treated between Port Mellon and Lund. Many sites had no re-growth, Lambert reported, and those that did consisted of small stems and damaged specimens.
In Powell River, the ministry of forests, lands and natural resource operations requested that a large patch of Japanese knotweed growing on the edge of Highway 101 in the Black Point area be treated. This was a continuation of an ongoing partnership between the ministry’s treatment team and Capilano.
Funding from Fortis BC increased significantly this year, Lambert said, which allowed a return visit to Texada Island for ongoing treatments of Tansy Ragwort along the Fortis right-of-way. A fast-growing, meadow-like plant, it is toxic to animals.
In 1986, the regional district held a referendum on Texada in which residents overwhelmingly supported the regional district adopting a policy to prevent use of pesticides, herbicides or other toxic chemicals on public lands on the island. The Texada OCP (official community plan) also calls for the avoidance of the use of pesticides and herbicides on forest land in the planning area.
Because of the policies, treatment on Texada involved mechanical removal, by hand pulling and digging, Lambert said, but this method is not effective. “It was noted that re-growth in areas pulled two years ago seemed similar or expanded from the original growth patterns,” he said. “It’s not going to work unless we use herbicides, period.”
Sites treated with a combination of stem injection and overspray were the most successful, Lambert explained.
Stem injection treatments for knotweed were carried out in high profile locations in the Roberts Creek and Gibsons areas of the Lower Sunshine Coast, where residents have historically been opposed to the use of any herbicides, Lambert said. “It seems the public is coming around to the fact that we have to use herbicides. There is no other effective method. Mechanical removal is just simply too expensive.”
Challenges remain, Lambert said, including the lack of an approved herbicide to use near water sources. While the City of Powell River contributed funds to CISC in its 2013 budget, the money became available too late in the year to treat a large patch of Japanese knotweed growing on the banks of Willingdon Creek. The timing, along with the lack of an approved herbicide to use next to water sources, meant the area was not treated.
