After 3 years with no success, I have finally managed to grow a cephalaria gigantea from seed. It popped up from nowhere a few weeks ago, and my heart lifted. It looks big and healthy, as opposed to the sick, yellowy, spotty things I have managed in the past.
We also moved a Geum Rivale from the front garden where it had been for over 10 years,when we had a big renovation last year, to the back, where its a lot hotter and drier. Its doing really well, has beautiful tiny nodding red flowers.