Here's a list of some plants that will grow in Zone 7.

Ornamental Onion Allium
Japanese Anemone (Anemone x "Queen Charlotte")
Sulpher Basket of Gold (Aurinia saxatilis 'Sulphureum')
Hollyhock (Alcea rosea)
Tuberous Begoniaz (Begonia x tuberhybrida "Camilla")
Japanese Boxwood (Buxus microphylla japonica)
Camellia (Camilla sasanqua 'Setsugekka')