Creeping Cinquefoil - Weed!

As a long-promised favour, I did the borders of a garden today for an old lady and they looked easy enough considering they hadn't been done for a couple of years. They were full of dog violets, burdock, spurg seedlings and grass (thankfully annual meadow type grass and not couch grass!).

But there was something else there I didn't recognise. It was like a type of buttercup with no flowers (thought it was creeping buttercup at first but noticed it had more leaves) andhad runners like strawberry plants which had ridiculous tap roots on the runners that were a nightmare to dig out. One came out whole and was about a foot long.

Got home and looked it up and it appears to be creeping cinquefoil. Has anybody had dealings with this weed before? It also grows right next to and under her established shrubs so weed killing is a dangerous tactic.

This weed seems as bad as ground elder or horse tails and that's saying a lot. Any ideas.... anybody!!?

 

http://www.lawnweeds.co.uk/creepingcinquefoil.html