I have to say that I have been advised that they can grow in sunny spots and some in the wild are growing out in open meadows in Croatia. I started mine from seed and after about two years growing them in pots, I had to get them in the ground. At the advice of a friend I put them in the sunny vegetable garden. They have been there for a few years and grew great. They are at least 12" across, with lots of flowers. I did not amend my soil, it is acidic in my area. I cut most of my leaves off in December or early March.

I think in the south they may need more shade but they are not just a shade plant.

Last fall I transplanted them from the veggie garden to a new bed. They are blooming without missing a beat.

Thought I would pass on my experience so it can broaden the use of them in different areas in the garden. Species hellebores I think are a bit more tricky to grow.

Good point about them not being acid-loving plants. I find a lot of people do mulch them along with all their other shade-garden plants, but hellebore are not a typical shade-garden plant!
The colors look lovely against the stone in your photos. It's too bad these flowers don't last very long when cut.