My perennial garden looks great in spring summer and fall, but when all the plants die back it's pretty blank. I'm looking for suggestions for small no more than 2' wide deciduous shrubs that would add interest and structure in the winter, but would also look well in other seasons. I don't like grasses. I get about 6 hours of sun each day. Soil is neutral. High humidity and very little rain in the summer. Thanks for your ideas.