If from one of the crosses involving semi-shrubby parents (Gold Collection is a marketing device used to sell multiple cultivars not all related to one another) and recently planted, maybe they froze. Otherwise perhaps the pathenogenic blackening that hellebores are prone to.

The lime statement would be based on what is said about hellebores in general. There is some thinking that the blackening is beaten back by reducing soil acidity with limestone; the same is also believed about peonies. However, I don't know that new plantings would necessarily die completely in a comparatively short time because the final planting site had not been limed.

This post was edited by bboy on Thu, Jan 9, 14 at 10:45

The several varieties I grow are in full bloom at the moment. Other than 'Pink Frost', which is H. lividus based, the rest of the collection should be fully hardy for this area - H. lividus is quite tender, so a more recent planting of that selection combined with our earlier cold snap could have experienced hardiness issues.

I've never found our acid soils to be much of an issue for any hellebore I've grown. And I've grown a bunch :-) Most plants tend to tolerate a relatively broad range of soil pH and unless it is skewed significantly one way or the other, less of an issue than most assume it to be. I'd expect the limiting factor to be poor drainage/excessive moisture followed closely by the hardiness issue mentioned previously.

If it is pathenogenic...

Here is a link that might be useful: Hellebore Leaf Spot