Craig Young
Hello again Deirdre, There are two main problems; The root system is extensive and if you miss any of it when digging it up it'll come back (even a cm of it!). There is a coating over the surface of the foliage which prevents systemic weed killers (such as round up) working. When I was at horticultural college they had a vegetable patch that was riddled with it. The solution they chose was pretty dramatic. They applied a special weed killer (only available to specially licenced gardeners) which killed every living organism in the soil - plant and insect. Then they covered it over with old carpet and planned to leave it for a year after which they planned to import all new soil and start again! I wouldn't suggest you go to these lengths!! What you can do is : dig up as much as you possibly can, stomp on any you can't dig up (between slabs etc) to bruise and damage the protective coating then spray it with a systemic weed killer, repeat till it starts die down a bit. Most importantly keep at it. Whenever you see even the tiniest new shoot dig it up. Good luck. Craig
