It is hardy. I have had one for several years & it was in a biggish pot. I planted it in the ground a few weeks ago as it was a bit restricted, so I’m hoping it will romp away next year.

Tough as old boot leather.

funnily enough I have never managed to keep it. So perhaps not so hardy in East Yorks.

More likely drowned than frozen out. They do like really well drained soil and as much sun as they can get.

Many thanks all. I do have a very sunny border but it is thick wealden clay. Perhaps a large well-drained pot is the answer.