Deer are a persistent problem for many gardeners because once they find plants they like, they will continue to feed on them. Prevention is the key! You can often dissuade them from munching in your garden by placing plants that they don't like to eat throughout your beds. While no plant is entirely "deer proof", there are many that are rarely damaged or seldom damaged. Be aware, however, that the resistance of plants to deer damage is often related to the availability of other food and when times get tough, deer are often forced to eat normally "resistant" plants!
Certain plants, like Hosta, Tulips, and Rhododendron, are "candy" to deer and are frequently severely damaged by these garden marauders. If these are planted in areas where deer are common, they should be protected by fencing or by some type of repellent.
There are many perennials and shrubs that are deer resistant and most of them are beautiful plants that you will love having in your perennial garden. Typically, deer steer away from plants that have thorns, fuzzy leaves or stems, coarse or tough leaves, plants with milky sap, and plants with aromatic foliage.
Below are some suggestions:
Shrubs: Abelia, Berberis (Barberry), Buddleia (Butterfly Bush), Buxus (Boxwood), Callicarpa (Beautyberry), Caryopteris (Blue Mist), Elaeagnus angustifolia (Russian Olive), Hibiscus syriacus (Rose of Sharon), many species of evergreen Ilex (Holly) including Ilex verticillata (Winterberry Holly), Mahonia (Oregon Grape Holly), Pieris japonica, Potentilla, Pyracantha (Firethorn), Spiraea, Syringa (Lilac), Viburnum, and Weigela. 
