a J.C.B.
this is one of the hardest weeds to get rid of.
it really depends on where it is.there are companys who will do it if its on a huge scale.
you have to dig dig and dig,but must not put the roots or anything in the green bins and im not even sure about the black one.
there isn't any easy way of getting rid.may be you should contact the council for there advice.
sorry.

Are you sure this is what you have ? Its almost impossible to shift can lift and push paving slabs sends roots down many feet so makes it impervious to any chemical control.

It can cost a huge sum to eridicate as needs all these roots removed to great depth and soil replaced , this is sifted to ensure not the slightest trace remains.Sorry this will not be cheap .Hope you have a small garden as this in a large one can run in to thousands to dispose of .

I would suggest you look at this site http://www.devon.gov.uk/index/environment/natural_environment/biodiversity/japanese_knotweed/knotweed_dos_and_donts.htm which has very clear 'do's' and 'don't's' for dealing with the serious weed. Specifically DO NOT dig up! But read all the info on the site. Realistically if this is what you have your are going to have to call in a specialist company.

Good luck Guest

Thanks for clarifying MG didnt make that clear did I ? Should have said it requires specialist treatment which is why makes it so expensive to deal with.

We have a large area by a pond affected, inside and outside a clump of bamboo.
I send my long suffering wife down there with a mattock and she chops the new sprouts of Japanese knotweed down every month or so during the summer.
While it will never be eradicated, it hasn't spread at all and causes no problems.
If you have a reasonably small garden just learn to live with it. I'd recommend snipping it off as soon as it appears using some handshears like the razor sharp Jakoti shears which are good for jobs like this.

That's okay BB we all post comments and then realise we should have added more info. I had always thought digging was the solution until I read the environmental advice.

Yes, Bertiefox, but in UK, what would you do with the bits you've dug out or chopped off? They cannot be disposed of in the rubbish or in the garden waste recycling, nor taken to the local tip, so unless you live somewhere where you can burn stuff frequently (out in the country, miles from anyone, but not allowed in towns and cities, mostly), you're a bit stuck. perhaps its different in France.