I have a plant that Siris sent to me earlier in the year. I dont know the answer but from what I can find the stems can lie down and root so its is left alone.

I hope Siris sees this question. I 'll send her a pm about it.

Hi Owdy, i do grow Iris confusa Martyn Rix. It is semi evergreen and the flowers appear at the ends of the stalk, small and blue. It does like a sheltered position otherwise the leaves and stems get brown and withered and look unsightly. If you cut them off green stems you wont get any flowers. You wouldnt get any on the brown dead stems anyway, so by allmeans cut those off, hoping they have made new runners for the future.
I think the solution is find a sheltered position it likes.
Good luck
Siris.

Ta.