WHAT TO KNOW ABOUT THIS INVASIVE PLANT
In order to treat Japanese Knotweed, you first need to understand what it is and how it affects the environment and structures sitting on top of and adjacent to the plant. To learn more, keep reading.
WHAT IS JAPANESE KNOTWEED?
Japanese knotweed is a highly destructive, invasive plant that is native to eastern Asia and brought to the U.S. in the late 1800s. It was used for many purposes such as an ornamental plant for gardens and erosion control along streambanks and slopes; thus begins the invasion. As it grew in popularity here in the States, it was vastly planted across landscapes in North America; however, those practices proved to be very damaging.
HOW DO YOU RECOGNIZE JAPANESE KNOTWEED?
Japanese Knotweed is distinguishable by the following features:
It can grow to stand over 10 feet tall
When sunlight is abundant, it can grow up to 8 inches a day
It's a lush green color
It has cordate (heart-shaped) green leaves
It is often mistaken for bamboo because of its similar hollow stems and growth nodes
It has small whitish-green flowers towards the end of the summer months, depending on its geographical location
Its leaves are roughly 4-7” in length and 3-4” in width
When sprouting from the ground, you will see red-tinged shoots breaking through
WHY IS JAPANESE KNOTWEED DESTRUCTIVE?
Japanese knotweed is known to have an extensive root system that can grow to extreme depths and can be detrimental to foundations and drainage systems. Knotweed also has the ability to grow through concrete and tarmac. As the plant grows in diameter, pressure is exerted, and this can lead to structures splitting or cracking at their weakest points.
In floodplains and shoreline habitats, knotweed is often transported by flowing water and will break off in one location only to root in new areas, which can restrict and choke waterways, changing the hydrological regime of an area and contribute to the loss of important habitats. Knotweed can also spread when roots are disposed of in compost or brush dumps and re-distributed in new places.
HOW DOES CRAWFORD LAND MANAGEMENT TREAT JAPANESE KNOTWEED?
Managing Japanese Knotweed should be left to experts who know how to carefully and effectively treat the plant. During the treatment process we perform stem injections of herbicide with a specialized injection gun during the late summer or early fall (when treatment is most effective). Knotweed requires multiple years of follow-up treatments to completely eradicate. Additional treatments are completed with either the same stem injection method or a low-volume, selective spray application or a swipe method of application, depending on the size and growth habit of the returning knotweed.
At Crawford Land Management, we are passionate about educating, restoring, and managing native plant communities and wildlife habitats. Japanese Knotweed can be destructive, but it doesn't have to be. Crawford Land Management is a full service natural resource management company.
If you're in need of Japanese knotweed eradication or would like more information on this unique plant, contact us at 508.477.1346 or info@crawfordlm.com.