I usually split mine after flowering but replant immediately. the roots are quite brittle so firm in to the prepared area. I also find they self sow readily and find seedlings within a few inches of the parent.

Most of them are cold weather growers, so it is reckoned that the optimum time is Autumn. Dig up a clump, gently tease the roots apart. Do not let the roots dry out, they hate that. Replant and water in.

Do not disturb the soil around them and you will find that they self-seed readily. I have black and white varieties but up to now, it's only the white ones that tend to produce seedlings although they are supposed to cross-pollinate; I have yet to have any success.

I will try that next year owd. I usually moved them after flowering as that's the time when I do most of the major weeding/digging and planting new perennials.

The advice came from Ashwood's Nursery owner, who is rather well known in Hellebore growing circles. Should be correct.

thank you all for answering my question.

a friend from here send to me the cutting about 3 years ago. I found last yeare a seedling but lost it dwe to dry summer. I think the best for Greek climate is to do the job now by cutting the roots