What does it take for a hellebore to open?

This hellebore (i think it's 'Ivory Prince') has been on the verge of opening for about two weeks now. I keep checking it every day to make sure i don't miss it.

This past Saturday i finished spring clean-up in the front yard. Here's what it currently looks like. You can't see that there are still crocuses blooming, the daffodils are definitely up, and the hyacinth started blooming the next day. 

 Here are some of my best crocuses this year ('Goldilocks' and 'Lady Killer').

And here are my ever-faithful bloodroot, just starting out. I probably left a slightly too thick layer of pine needs on them last fall, but after i had finished cleanup in the front yard on Saturday, i ran out of steam to continue in the back.