You have my sympathy about your problem with deer. They have decimated many of my plants too, especially in very cold winters. Where I live, they are especially fond of arborvitae and holly. They have also nibbled and seriously damaged the bark of numerous young trees.
I have found two solutions to be helpful, one that takes a lot of work and one that is a lot easier. First, in late fall, before the deer have established their winter feeding habits, I have sprayed plants with a homemade hot pepper concoction or hung sacks of Milorganite on branches. These solutions seem to work but are time-consuming, and sacks of Milorganite are kind of ugly hanging from the branches.
More recently, I purchased 100 feet of 4' high black plastic-covered hardware cloth cut in a variety of lengths and used them to surround the plants I know the deer like. Some 2' long pieces are used to surround young tree trunks. Some longer pieces surround a group of shrubs. I have also used sections of decorative black plastic-covered metal fencing sold by Lowe's for the same purpose. The fencing solutions are more attractive (to me anyway) than bags of Milorganite. Here is the Lowe's fence:
In my gardens, the deer have ignored unprotected spirea, dwarf Alberta spruce, Chaemocyparis, Rose of Sharon and lilacs. They love daylilies, especially the prettiest ones, crape myrtle, hosta, and the flower buds of rhododendrons. So I have used the hot pepper spray on the daylilies as soon as the buds have formed, and the deer have learned to leave them alone. I think the key is to use the spray early to train the deer to stay away.
