Our yard is fenced, with wire mesh in the back, and redwood the rest of the way around. We've lived here nearly two years now, and never had any deer in the yard. However, they come down the street in the front, and they'll eat the gardenias and roses. I'm told that scattering shavings of Irish Spring soap around them helps, but won't stop them if they're really hungry.
If you plant things they don't like the smell of will help some .. Marigolds are one flower they tend to stay way from.
It's good that your yard is fenced in to protect your backyard. Down at my mother's neighborhood, many of the neighbors put chicken wire fences around many bushes and plants to protect them from all the deer.
Get a paintball gun and ambush them.
The paint won't hurt them, but it will scare them off.
It also works great on dogs, racoons or possums that tump over garbage cans.
So9