Round-up but don't get it on any of your other plants.

Agree. Roundup. You may need 2 or 3 applications to achieve total success.

And don't waste your money on the ready mixed stuff, get the stuff you have to dilute for yourself. It is a lot cheaper. Add a little soap (for one Fairy will do) a couple of drops in a litre of water. It helps the weedkiller stick to the leaves.

Round up is what I use but it comes back from next door every year.

Dig out as much as you can and use Round Up whenever you see new growth. Have a read of my profile and see what also worked for me

Thank you, my friends.