I don't really want to rip all the plants out now at the worst time of the year, and have them hanging around whilst normal liquid dpm dries and wait for blocks to dry out etc...
So why not delay till say late Aug/Sept or the autmumn when the plants are past their best?
My own addition to this and what we did in my brother's terraced garden was to add a 2 inch sheet of polystyrene insulation board against the wall between the dpm and the soil. It's fairly "waterproof" itself and also protects the dpm from stone damage. Been there three years now and the render's not blown off it (yet??)
Ideally I want to get the rendering fixed this year. I was trying to avoid doing the rendering first, then disrupting everything around it...