I've grown the rock hardy Epimedium x rubrum for a few years now. Last year I planted these:

E. davidii

E. diphyllum 'Roseum'

E. grandiflorum

E. lishihchenii

E. stellatum 'Wudang Star'

E. x youngianum 'Niveum'

The surprise is that that they have all survived in not so good conditions: in a "raised" bed(a whole 8 inches) edging a shoveled sidwalk -but there was no snow, and only 1.5 inches of leaf mulch.

Rick