My Eryngium Planum survived this last winter up to its ankles in snow with the leaves still showing. So I guess it must be a pretty tough plant and keeps its leaves all winter. It is the best its ever been, with lots of shoots. I love the way it turns a bright electric blue, just when you think it will stay green.

Ours is fully herbaceous meaning it dies back completely in winter and grows again in spring.

No, its not, in short. But it will come back next year, as the others have said.