Japanese knotweed is considered one of the world’s most aggressive invasive species. Its ability to propagate from cuttings or plant parts have led to it being classified as “Controlled Waste” in Britain, where it’s illegal to plant or spread. Uprooted Japanese Knotweed in the U.K. must be burned or go to a licensed disposal facility.
The species can be identified by its oval leaves and hollow stems with distinct nodes that resemble young bamboo plants.
Stems may reach 12 feet tall each year, even after they are cut back to the ground. The flowers are compound vertical blossoms, cream or white, that appear in late summer or early fall.
Wulfken warned that getting rid of the plant is difficult, as if it’s cut down, it vigorously re-sprouts from its roots.
The most effective method of control is by killing the entire plant, including the roots by using a specific herbicide application method just prior to its flowering stage, or about now — late summer.
This method calls for injecting a small amount of herbicide into the hollow stems, so it flows down into the roots.
Kathy Bozony, Natural Resource Specialist for the environmental group Fund for Lake George, explained the process to the members several weeks ago to the Northern Lake George Rotary Club.
In her talk on Japanese Knotweed, she warned the Rotarians about how pervasive it now was in Bolton, Hague and Silver Bay, among other lakeside communities.
The hypodermic-like device she described is manufactured by JK Injection Systems, and costs about $200. She recommended using the herbicide Habitat or Aquamaster, substances that can be used near waterways, or the more common Rodeo —all of which are glyphosate preparations.
Plant has its positive aspects
In the meantime, people can make Japanese Knotweed tea or cook the leaves, which are a good a source of resveratrol, which can reduce blood sugar levels, serves as an anti-inflammatory agent, and boosts longevity in some vertebrates.
Furthermore, it is believed to combat cancer, slow tumor growth and may be an anti-aging compound. Also, some studies indicate it can dramatically reduce plaque deposits in brains, and may serve to slow or reverse Alzheimer’s symptoms.
However, Japanese Knotweed does spread like crazy and overpower native plants, Bozony warned, as she lauded the new momentum in Warrensburg to rein in the spread of the pervasive plant.
“If this campaign is conducted as a community effort over several years, it will go a long way to keep Japanese Knotweed under control,” she said.