I would definitely advise Round-up, available widely. Buy the concentrate, mix with water as per instructions, and use a garden spray (or watering can with a fine rose) on the LEAVES - do not cut off the leaves first, as RU works best on broad leaves. It then penetrates to the roots and kills upwards, so you won't see much result for a few days. RU only kills what it touches and doesn't spread sideways in soil, and is safe for animal/offspring access after about 30 mins or so. It may be necessary to give leaves a second dose as some perennials are quite "sturdy". A pot of RU Conc is not cheap (around �20) but it goes a long way, and it does work. Sodium Chlorate is OK but it does spread in soil. Don't use RU in windy conditions or when rain (HAHAHA) is forecast, spray carefully - just enough to cover the leaves without drips. Weed burners are OK for a temp. solution but there are not many "systemic" weed-killers available to deal with remaining roots effectively. Pathclear is OK but doesn't have the clout of RU. Good luck - and no, I don't work for a company which supplies this ! - just I have to do a lot of weed clearance in my chosen walk-of-life and to my mind, RU does the job very well. I have used it with good success on real horrors like bidweed, ground elder and couch grass. It is essential to spray it on the leaves, though. Again, good luck, Osprey