An invasive plant, Japanese knotweed is not native to the United Kingdom and can cause a variety of problems both in your yard and in the biodiversity of the rest of the country.
Closely resembling bamboo, Japanese knotweed is an invasive threat that tends to grow in clumps—some that can reach 13 feet tall—and destroy areas where they can get a foothold. They reason being is that these particular plants grow “knots” or joints every few inches, meaning their growth can overtake footpaths, break apart concrete, ruin a tarmac, and even devastate the edge of river banks causing immeasurable flooding.
Identifying the Troublemaker
Besides looking similarly, as previously mentioned, the Japanese knotweed also features heart-shaped leaves that are about the size of the palm of your hand, with a red vein running down the middle.
Its leaves are as large as six inches long by four inches wide, oval or triangular, and pointed at the tip. The flowers are very small, white to green, and grow in drooping clusters. Seeds form soon after flowers bloom and are triangular, shiny, and winged. Also note the flowers that grow atop the plants are cream-colored and grow straight up.
You’ll most likely find these plants in damp areas around your home or lawn, which take hold in soil with that’s rich in nutrients.
Ridding Yourself of Japanese Knotweed
Killing Japanese knotweed can be an annoyingly slow process. Because the plant spreads underground, you’re going to have to be persistent to be successful.
Like most weeds, a common method to kill Japanese knotweed is by using a glyphosate- based herbicide; think products like Round-Up. The trick is to use an undiluted or high- concentration formula, because this is one hearty plant. You’ll want to keep applying it regularly to ensure that the plant expends its energy trying to grow, eventually “suffocating” itself.
Because there are lot of rules regarding the disposal of this highly-invasive weed, you’re also welcome to call a professional service to do it for you. There are even some services that will come spray your Japanese knotweed for free!
Whether you decide to mow and spray, dig it out, or call a professional, be sure to adhere to the disposal rules in your area. For example, you must comply with specific legal responsibilities, including:
- spraying invasive plants with herbicide
- cutting and burning invasive plants
- burying invasive plant material on site
- disposing of invasive plants and contaminated soil off site
And finally, you should know that you don’t have a responsibility to remove the plants if you don’t want to. However, you must not allow Japanese knotweed to spread onto adjacent lands, or encourage its spread outside of your own property.