The USDA estimates that Japanese Knotweed spreads at a rate of 30% to 50% yearly if unchecked. The Board of Selectmen has chosen herbicides as the way to control knotweed. This involves the repetitive use of herbicides to slowly kill the plant. In some cases, the stem of the plant will actually be injected to kill it at its root. This option is by no means a quick solution and can often take months, even years, to properly eradicate or control the knotweed.

The program will start this fall and continue next spring. It will start at the Franklin-Andover town line and at the Andover-Salisbury town line in September. If you would like to help or want more information, please contact us at 735-5332.

Japanese Knotweed is native to Eastern Asia and was introduced to North America in the 19th century. Knotweed does very well along roadways and rivers. It reproduces by seed and through large root systems, which may reach a length of 40 to 60 feet. A small piece of root can float down a river and begin to grow once it is deposited on land. These buried roots have grown through two inches of asphalt!

The heart-shaped leaves are arranged alternately along the stem. The leaves are normally about six inches long by three to four inches wide. Minute greenish-white flowers are produced in axillary panicles.

This plant is a threat to native vegetation because it often forms dense patches which shade out all other plants. It is a particular threat in wetland areas, where it can survive floods and quickly colonize scoured stream banks. Japanese Knotweed is difficult to eradicate once it has become established.