Is there anything that can get rid of japanese knotweed?

Question

its a rampant weed.

Answer 1

We use a stronger version of 'roundup' called 'Clinic'.

You need a licence to buy it though.

Answer 2

Close to water, chemical control is better with with herbicides containing glyphosate.  Spraying both the top and under leaves will improve control. If you decide to cut, it should be done very carefully using a hand scythe to avoid spreading stem fragments. Don't use a mower or strimmer as this will spread the broken stems and you're back where you started. Keep cutting every 2-4 weeks to reduce both above and below ground biomass. You can also uproot the stems by pulling from the base in late spring early summer onwards, again making sure you don't leave any lying around.  Roundup, Garlon 4, Tordon 22 and Evade are all good for killing the plant as long as you are not growing vegetables (some farmers use it). It is a persistent and long term weedkiller so make sure you follow the instructions carefully and check you are able to use it in a garden. Finally if you do cut it, burn it rather than taking it to a tip. You would have to take it to a controlled dump anyway.

Answer 3

In my experience a 5 kilotonne nuclear warhead might just about do it.

Answer 4

Apart from carefully digging out the plants and every fragment of it's roots and disposing of it as special waste in a liscanced landfill it is nearly impossible to get rid of.  Usually digging it out isn't viable as the roots can travel several metres below ground so you would end up with an excavation the size of an olympic size swimming pool.  Glyphosate will work eventually but will take several years of repeated application before it weakens and eventually kills the plant.  Whatever you do, don't cut the stuff and put it with your other garden waste - you only spread it and will make the problem much worse.  It is also illegal to do this.  Picloram is very effective but you cant use this near water.  There are a number of campanies make a living out of eradicating Japanese Knotweed. You could contact your local council for advice.  Good luck !