Introduced weed a knotty problem

  • Jul. 15, 2005 10:00 a.m.

By Heather Ramsay-To some they are pretty flowers for the garden, but to others they are invasive weeds choking out native plants.
Even Mike Cheney can agree Japanese and Himalayan knotweed are beautiful plants, but that won’t stop him from experimenting with ways to kill what is “growing like a weed” on the islands.
The plant is already a huge issue in Great Britian, where it has been busting through pavement and even into Welsh stone masonry homes, and laws have been passed which prohibit the introduction or movement of Japanese knotweed.
Mr. Cheney, who is working on contract with the Ministry of Forests and the Northwest Invasive Plant Council, says although there are many invasive plants on the islands, this is one he feels he may have success with.
He is experimenting with a few different methods of killing off the weed.
One involves spraying patches with salt water at regular intervals and the other involves covering the plant with black plastic and wood chips to keep out the sunlight.
He says world experts are skeptical of his experiment with salt water, but he is finding it kills the leaves of the plant. With successive sprays, the plant is unable to photosynthesize and is weakened, he says.
“If a plant can’t put out leaves to collect light, it won’t survive,” says Mr. Cheney.
His experiment covering the plants with plastic and sawdust has a similar effect, but works better on the Himalayan variety, he says.
He doesn’t believe chemical pesticides are an effective method to control the plant as it regenerates so easily.
“It’s an all or nothing thing. If you don’t get everything [the plant] will grow again,” says Mr. Cheney.
It is also important not to use a blade to tear at these patches, he says, because just one gram of the root or stem can set the plant off again.
“If it ends up travelling on a hoe and lands in the right growing condition, you could have a major patch again after four years,” says Mr. Cheney.
Japanese knotweed, also known as Mexican bamboo or wild rhubarb, is a pioneer species in volcanic areas, breaking up rock so other plants can take root.
“Imagine how tough it is if it drills holes in lava,” he says.
He is trying to deal with patches accessible to humans first, such as on roadsides or in public fields.
Another species Mr. Cheney is concerned about is gorse, a spiny Mediterranean shrub he believes was first introduced on Lina Island. The plant has now spread to the surrounding islands, including Maude Island. He’s also found it on Kumdis Island and in a field across from SuperValu in Sandspit.
Once it gets started, this plant grows high very quickly, then falls and takes root where the branches touch the ground.
Marsh thistle is another concern, but as far as he knows there is only one site on the islands, which he is planning to treat.
If all other eradication methods fail, check out the recipe for apple and knotweed pie at www.wildmanstevebrill.com/Plants.Folder/Knotweed.html.

Just Posted

Haida Gwaii art gala seeks submissions

Annual fundraiser supports local artists and programs

PHOTO GALLERY: Masset takes off on Terry Fox Run

More than $1,000 raised for Terry Fox Foundation

B.C. offers early retirement, training fund for forest workers

Communities eligible for $100,000 for permanent closures

Prince Rupert’s ferry issue is a North Coast issue, MLA Rice

Prince Rupert not alone in fight to save ferry to Ketchikan: Alaskan Rep. Ortiz

Brand new vessel for Massett Marine Rescue

The Tagwaal was unveiled to the public Sept. 6

Third instance of Trudeau in skin-darkening makeup emerges

Another instance of Trudeau using makeup to darken his face has emerged, within 24 hours of the first

B.C. MLA’s former constituency assistant charged with fraud, breach of trust

Charges announced Sept. 19 more than two years after Martin fired Desmond Devnich for alleged thefts

B.C. salmon farm inspection deal reached with Indigenous people

Monitoring to determine if any Broughton region farms stay open

RCMP seize $1.9 million in B.C. traffic stop

The driver and passenger were detained under the Controlled Drugs and Substances Act

Yearbook photo surfaces of Trudeau wearing ‘brownface’ costume in 2001

The report describes the occasion as an ‘Arabian Nights’-themed gala event

‘Troubling, insulting’: NDP Leader Jagmeet Singh reacts to Trudeau’s brownface photo

Jagmeet Singh, leader of the New Democrats, responded with a call for love after Trudeau photos surface

35 of 87 dogs in 2018 Williams Lake seizure were euthanized, BC SPCA confirm

The dogs did not respond to the behaviour modification and remained terrified of humans

Elderly B.C. man gets 10 years in prison for sexually abusing young daughters

WARNING: This story contains graphic details and is not appropriate for all readers

Most Read