Posted: 22/05/2016 at 09:24
No need to panic! Looks like a good crop of Green Alkanet with some Herb Robert (a wild geranium with smelly foliage) and some other odds and ends. Get yourself some sturdy gardening gloves and a long sleeved jacket (alkanet can be a bit bristly) and pull them out then dig up the roots.
Then, if you get more than a little regrowth I'd spray it with a weedkiller containing glyphosate - leave it for a fortnight to go brown (this indicates that the roots are dead) and pull it up again and dig over. You should then have a border ready to add some organic matter and get on with planting.