Some are deciduous (herbaceous perennials) others are evergreen, depends on variety. And there is a semi evergreen one too...

The beauty of them is that they hang on to their leaves right through winter. True, some can look a bit rough after a few weeks of cold, but we all can! Best practice is to cut off all the tough old leaves at the end of winter, early enough so you avoid having to dodge the emerging new leaves, so about late Jan/early Feb. Then, watch out for the flowers which emerge with the new growth. Good time to mulch/light feed (they're not demanding) when you've cut off the old leaves, as that way it's easy to chuck compost about without covering leaves. I've found that the only 'pests', if you can call them that, are leaf cutter bees which often cut neat holes in the older leaves for their grubs to grow in and hatch out from. I don't mind, they've got to live, too. Worthy

I have a group of fully deciduous ones as well as a fully evergreen one and 3 others that sometimes do drop their leaves. So as bamboo said it is a species as well as a varietal thing. I tidy up the tatty leaves where possible as Worthy has already suggested. Though one of mine is slug bait for some reason :o(

That is very helpful thank you all of you. It is the first time I have grown them. I will give them a trim later on like you suggest. They are looking in quite an unattractive stage at the moment.

My bit of garden downstairs looks as if the apocalypse arrived when I wasn't looking, and as for the balcony, well, terrible, it's been given over to the birds and their doings... Still, something to do in early Spring, lol!