Mine are in the garden soil and I never move them. I dead head and I do feed but nothing else and they come up year after year.

you can propagate them from root cuttings. if you try and dig a bit out and leave roots behind they resprout.

Same as Drc726 mine have been in the ground for a few years other than dead heading them they are no trouble one of mine is just behind my azalea in my photos

and i meant to say apart from a ring stake to stop them flopping I dont do anything to them either.

Never have to stake mine SBG, but thanks for the idea of root cuttings as I have one I would like another of, so whens the best time to take theses cuttings?

Thank you to all for your response. I too would like to know when the best time is to take root cuttings?

now is a good a time as any.. choose roots about pencil thickness. the lowwest bit cut diagonal the top square and repeat up the root. then pop diagonal bits into gritty soil, covere over. water and wait.
it is really easy.