Question: what plants are winter hardy?
Answer: Chimonanthus praecox. Although very much a background shrub in summer, this Chinese native makes a particularly fine display throughout winter. ... 
Viburnum x bodnantense 'Charles Lamont' ... 
Sarcococca. ... 
Clematis cirrhosa. ... 
Cornus. ... 
Prunus x subhirtella 'Autumnalis Rosea' ... 
Holly. ... 
Yew.