How To Get Rid of Japanese Knotweed

By Subodh / December 2, 2013

The Japanese knotweed also called Polygonum cuspidatum is considered as a highly invasive weed. While you may be armed with vast knowledge on gardening and ways of controlling pests and weeds perhaps you can also take some time to understand how menacing the Japanese knotweed is and consider some of the ways to control and eradicate this weed.

The Japanese knotweed has a way of wasting your chances of nurturing a beautiful landscape and hence you must be able to carry out a first line of defense to save the plants and the landscape’s beauty. This weed is found in the US, and UK and has characteristic Godzilla like qualities.

How to Get Rid of Japanese Knotweed

Japanese knotweed plants were first introduced in the UK from Japan and eventually into North America within the 19th century. It was mistakenly thought that they were suitable as ornamental landscaping plants but has since spread out like wildfire and become just a weed.

They will grow well near riverbanks, road sides and even your lawns looking to conquer any land that they can grow on. Generally the weed spreads through landfills and it only requires a root of the weed and adequately fertile soil and the wildfire kicks off. The weed eventually crowds out other plants on the land and become a choking menace.

Considering the aggressiveness with which this weed covers any land it is only fortunate that the knotweed never invades forest land otherwise it would just be a mater of time before the forest is completely choked out. The weed specifically targets friable soils and exposed lands that have ample sunshine. If you are bordering a forest and notice this invasive plant you might consider eradicating it before you can think of the forest.

Definitely if you do not do this the killer bamboo will gracefully spread into your lawns and gardens at an incredible pace that will overwhelm you. Possibly you also might want to know that eradicating this killer bamboo is not as easy as it look. Therefore careful planning and use of appropriate methods is the only sure way of beating this menace.

What makes the control of this weed extremely difficult is the fact that it colonizes any available space including those cracks on the concrete sidewalks. Therefore whenever the Japanese bamboo as it is sometimes called has been identified, you should be ready to put in a spirited fight otherwise it will overrun your garden and lawns.

Because of the sheer determination that this Japanese knotweed shows it is only wise that you have a number of options up your sleeve once to choose to eliminate it. Certainly you may first of all want to just suppress the onslaught although it would be much better to eliminate the weed.

This requires that you make use of tarps to cover and smother the seedlings. These tarps can be used to cover the area in early spring and this will effectively eliminate any chance of the Japanese knotweed growing there.

Certainly as you use the tarps over a large area you may as well apply mulch and plant over some shallow root plants that will still do well. However just ensure that the ‘enemy under’ finds no space for sunshine and dies a sunless death even as the plants you have put on top of the tarp some of which may be potted grow happily.

Alternatively you can choose to use some old carpets as well to smother the Japanese knotweed. However what you must ascertain is that the weed does not get anywhere near sunlight and this depravity will cost its life. If there is a way that you will use the old carpet but it does not appear as trash then you can try this option.

However it may be that the trash pick up will spot your old carpet covering and mistake it for trash. Furthermore the seams on the carpet may provide a reprieve for the smothering weed that will push its way through. This is why tarp should be your best bet on this method of control.

Because of the nature of this weed and its aggressive spread you might consider using a chemical like Roundup that is usually applied as a foliar spray. When using this foliar spray you should apply the spray most appropriately during late summer or early fall. In this way you are assured that the spray will go all the way to the rhizomes apart from incapacitating the flowers. The process must be repeated after a while to ensure that the control is effective sometimes a spray of glyphosphate during the growing season will also retard the growth and eradicate this menacing weed.

Alternatively you can also cut it back in summer, in which case its photosynthesis is checked and never permitted to operate at adequate levels. Because cutting the Japanese knotweed causes it to easily sprout new roots and encroach itself in your landscape or garden always rid the garden off the cuttings.

Generally in orders to ensure effectiveness don’t depend on the cutting method only but use it in conjunction with other methods of control. For example you can use this tactic together with injections administered into the stumps of the weed although this can be very labor intensive.

Alternatively you can dig out the rhizomes from an infested area. These can also be carried away and destroyed. Most of the time these rhizomes from matured weeds are often woody and bulky.