Posted: 29/08/2013 at 11:06
Thanks everyone, it's been a great success. I moved all the plants into quarantine and sprayed the whole patch with glyphosate. I put some leftover supermarket herbs in a couple of months ago (thyme, basil, parsley) and they have done well. Yesterday I dug out all the dead foliage in the rest of it and the mangy rose, and dug in fertiliser and some more compost. A nice lovage plant survived, and some marjoram, and to my surprise the chard. The chard bolted when moved and I thought it had died, but there are some fine new leaves coming up. It will probably bolt again now I've moved it back! I added lemon thyme, sage and tarragon, and it's looking lovely.
Now, the rose. I was going to get one of the gorgeous ones recommended above, but I've had so much trouble with deer eating the roses on the other side of the house I'm not sure it would be a good move. I might try it, but I might go for a passionflower or clematis instead.