What is it?
Japanese knotweed is a non-native invasive shrub that is native to several countries in eastern Asia. Also known as Japanese bamboo, Mexican bamboo, and fleeceflower, it can form very dense stands that shade out, outcompete, and prevent the germination of native plants.
Japanese knotweed spreads primarily by rhizomes (underground stems) and also by seeds. It tolerates a wide range of growing conditions and has the potential to become a much worse problem in Kentucky than is currently seen.
How do I control it?
Japanese knotweed has proven to be very difficult to control. Its vigorous growth in addition to its large root system and ability to grow in a wide range of conditions makes it a plant of great concern. New Japanese knotweed plants will develop from rhizomes, and any part left in the ground will begin producing a new plant almost immediately. When removing a Japanese knotweed plant, remember that an entire stand can be essentially one big plant. The key to controlling Japanese knotweed is killing the root system. The most common methods of control are mechanical removal, herbicide application, and a combination of mechanical and herbicide methods.
For more control methods, click the Kentucky Woodlands Magazine article link to the right.