I wouldn't leave anything out at night until at least the end of may unless you are really warm and sheltered

Thanks for that. I will leave them tucked up for now!!

You can teave them in a sheltered spot to harden off as long as its fine and dry, during the day mine go under like a carport shelter to keep the worst of the weather off

Or you could put one of the small round bell shape clear plastic covers over them (like a mini greenhouse effect)
these will let the plants roots grow and help the hardening off,
Mysembrianthemums, like nothing better than to open out in the sun, so a nice sunny site for these.

Thanks for all your help. I had some a couple of years ago I and they were excellent. My Dad used to grow them so they bring back m e memories of my Dads wonderful garden.

Wendikins,
thats a wonderful reason to grow anything,
these are flowers that only open their heads when its a nice sunny day 'enjoy the happy face of you know who when the suns out'.