In late winter, if deer populations are large and more palatable food is scarce or covered by deep snow, deer will eat almost any plant. Very hungry deer will eat thorny plants, such as barberry, buckthorn, red cedar, and Russian olive, as well as bad tasting plants like honey- suckle, balsam firs, potentilla, lilac, and spirea. An eight foot tall fence is about the only sure way to exclude deer. Unfortunately, a tall fence encircling your property is expensive and unsightly. A cheaper but less effective tactic is to enclose plants with snow fence.
Deer usually avoid small, penned-in areas.
Covering lower branches with netting is of little benefit. You could also try repellents. Deer-Off is reputed to last twice as long as most repellents because rain or snow will not wash it off. It is available in a ready to use spray or a concentrate. All these products either taste bad, smell nasty, or are associated with humans.