Maple Ridge will look at its budget for next year and see if there’s any room to finance a war on invasive plants, with Japanese knotweed at the top of the hit list.
With money available, and depending on advice of a committee, the district could hire a consultant to do a map and inventory then hire a pesticide applicator to terminate the plants with direct injections of glyphosate, the only method of killing the invader.
But the public should keep in mind that Japanese knotweed isn’t the only nasty plant out there. And while knotweed can crumble concrete with its extensive root system it’s not dangerous to people like giant hogweed is, the sap from which can cause lasting burns or even blindness.
Parks and facilities director David Boag told council Monday that while knotweed won’t hurt you like hogweed, “if it’s (knotweed) grown by the side of your house it has the potential to damage your foundation.”
But he downplayed comments from the Invasive Species Council of Metro Vancouver which said the weed can bore through metres of concrete.
Boag said he couldn’t find any examples of knotweed doing that.
But he also said injection with the herbicide glyphosate is the only way to kill the plants. Digging up the roots is impossible and cutting it only spreads it more. Each site may need to be treated for as long as four years, he added.
He also hinted that Maple Ridge may never be able to exterminate the invasive plant which originally sold in nurseries as an ornamental plant.
“I think it’s here. We’re never going to get rid of it.”
So far, at this point, knotweed is not spread aerially, although possible cross breeding could see that happening. The plant is a favorite of honey bees when the flowers bloom in late summer.
While work is underway along the provincial Lougheed Highway to kill the plants, Maple Ridge is responsible for removing the plant from its roadsides, while a bylaw change may be needed to require private property owners have to remove it from theirs.
He told council that hiring a qualified pesticide applicator is the only choice for homeowners, and warned council about hiring its own contractor because the word is out that municipalities could be spending lots of money on the issue.
Staff also will prepare material to inform the public about weeds and the best way to deal with them.
Municipal bylaws against using cosmetic pesticides are superseded by the B.C. Weed Control Act.
Coun. Al Hogarth said he’s more concerned about the spread of blackberries but Coun. Cheryl Ashlie said the Japanese knotweed is far more serious.
“This has the potential to have an economic impact.”
She said Maple Ridge should learn from the U.K. where the plant has spread with economic consequences.
“We should get in front of this before it is an economic factor and people are being impacted by it.”