can you add a picture showing what it is like at base and then I will have an image to look at. I know the flowers but not the root stock. I suspect it will be a case of dividing it late autumn early spring as you would do with many other perennials. Never tried cuttings so don't know.

Hi, there are 3 ways to propagate these, seed in containers, in a cold frame in spring, basal cuttings in spring, or root cuttings in winter, Derek.

Sorry for my delay in answering and thanking you sbg and Derekm. It looks as though I will try root cuttings. Thanks to you both.