Arborvitae grow across eastern Canada and the United States. These soft evergreens produce multi-lobed, scaled leaves that retain their color in the winter. In the wild, arborvitae serve as winter sustenance for herbivores like deer, though deer love to munch on it all year round. Arborvitae may be a life-saver in the wild, but gardeners trying to maintain their arborvitae topiaries may get frustrated by deer nibbling on it. Since you can't eliminate the deer, the best way to save your arborvitae is to repel them.
Pound five-foot pieces of iron rebar into the ground at three-foot intervals in a circle around your arborvitae. Leave a 10-inch border between the circle of rebar and the trees' branches.
Connect the rebar with plastic snow fencing by wrapping it around the circles the rebar creates. Secure it to the rebar with the wires provided in the snow fence kit. This prevents the deer from getting to the arborvitae.
Scatter bloodmeal around the outside of the snow fence. Blood means danger to deer; the scent should frighten them away. Reapply the bloodmeal every three weeks and after heavy snows and rain.
Mix several cloves of garlic with cayenne pepper in a blender to create a paste. Paint or spray the mixture about halfway up each tree. If the deer manage to get past everything else, the scent and taste of the spray should drive them off.