Once (so far), Polly;-) I think that you will find this rose too tough for a weedkiller to have much effect. The only solution is to dig, dig and then dig some more until you have all the runners out. If you want to keep the rose then try a metal, or plastic, barrier sunk into the ground around it.

You may find also the hips are seeding underneath the parents making the whole area thicker with growth.

Thanks, have been digging and digging and then some more. Shame really as it is a really pretty open scented rose. A barrier might be the answer as most of the runners are quite shallow. Again my thanks. Polly

You can also trim this one back quite brutally with hedge trimmers, in the autumn and then again after first flowering is over around July for a second show later.

Thank you. I was wondering if I could 'hack' at it...(cut it back). All but the 'parent(s)' are out, so it's a pick axe on Wednesday if we are buried under snow by then.

Ouch ... pick axe is really brutal, but what must be, must be!! When you have down-sized the plant, good clean cuts will stop too much die back after hedge-trimming. I hedge-trim, then go over with secateurs just tidying up any shredded edges.

My half dozen 'whips' were in the middle of a bed and have taken over so it's 'off with their heads'. (Remove them totally) and hope to find a patch elsewhere for them. thank you all for your ideas.