Herbicides Against Japanese Knotweed

One of the most effective herbicide active ingredients for Japanese knotweed control is actually called glyphosate. 

It is really effective in Japanese knotweed control because it disrupts the biochemical pathways of the plant for making plant proteins that are essential for the invasive weed to live and grow.  The herbicide soaks through the Japanese knotweed leaves and is taken into the root system of the plant. 

The knotweed forms dense clumps that can grow up to three metres. It has large, ovate green leaves and a stem that is hollow.  Japanese knotweed stems are similar in appearance to those of bamboo.

The greater the number of Japanese knotweed green leaves that are showing, the more glyphosate can be absorbed into the Japanese plant, so encouraging Japanese knotweed eradication.

Japanese knotweed control using herbicide can be carried out during the growing season when the plant has some green, leafy material present.  The control with herbicide treatments takes effect usually within a few weeks but Japanese knotweed eradication can take a minimum of two sprays of Japanese knotweed in one growing season to complete the complete eradication.

Japanese knotweed control by this method can take up to ten days for the Japanese knotweed plant to begin to die off after the Japanese knotweed control treatment has been applied. It is important to always watch for re-growth of Japanese knotweed though as long as every part of the plant is not dead, it may grow back up.

Another method of Japanese knotweed control is in the removal of the ground contaminated by it. Care should be taken with the roots when Japanese knotweed removal is in progress, more rather than less is the rule with Japanese knotweed removal of roots.  One tiny piece of Japanese knotweed can actually produce more Japanese knotweed in a very short time. 

Even with care during the Japanese knotweed removal, it is advised that a Japanese knotweed spraying programme be embarked upon to fully ensure the Japanese knotweed eradication.  The control of the weed is impossible to prevent if fragments of Japanese knotweed are not sufficiently eradicated from the contaminated ground.

It is best to leave the eradication to a competent manager perfectly trained to deal with those situations. And a perfect eradication would need a follow on treatment to make sure that the invasive plant does not grow back and that all the roots have been removed from the ground.