Dying cistus

It’s on the left in this pic from earlier in the year

Oops, forgot to load pic

Perhaps it's suffering rather belatedly from the drought conditions earlier in the year although they do like a sunny position.
I think I would give it a severe pruning and see what happens. We had a cistus years ago and it thrived but didn't appreciate being moved; we bought another one which never thrived but was apparently in the wrong place, not sunny enough.

ps cut the dead part right out but try to save some of it to keep a shape.

Thanks Jalima - would you chop it about now, or leave til Spring?

I think they are supposed to be pruned after flowering. There’s a distant memory of being told to prune them like lavender, so not to cut into the old wood. Think I’d play a wait and see game with it, but that’s what I do with most garden issues. .

eeek - I've just read that they should not be pruned too much.

However, you could start by cutting into what looks like dead wood and see if there is any life lower down. If so, chop that far, but if it looks dead further down then chop that out.

www.sundaygardener.co.uk/cistus.html
you could strike some cuttings just in case

From the link, it seems to say you can prune it, even into old wood, which is unusual / unlikely advice. I think I’ll wait and see

I should add that I've not managed to keep one yet ….
But I have never pruned one drastically either.

I'd be surprised if the summer drought is responsible for the die back. Cistus grow in hot, dry Mediterranean areas. I thought they liked light pruning - like lavenders. They do deteriorate relatively quickly and cuttings should be taken every. three or four years to replace the mother plant. I think the plant might be on its way out. You might as well cut out the dead wood anyway, you have nothing to lose, but scratch the bark with your thumb nail first to see if it is green underneath. If so, it isn't dead. Just a long shot, could a dog have cocked its leg over it and scorched the centre?