Rabbits!

[GhettoGardener]

Buy some habanero peppers. Throw em in the blender with some water. Strain out the solids so you're left with homemade pepper spray. This can be mixed with compost tea (don't put the compost tea in your blender obviously). Put your solution in a spray bottle and spray the foliage you want to protect. I'm sure once the bunnies or whatever is munching on your leaves will think twice after taking one nibble. HEHEHEHEHEH!!!!!

[Charm Dreier]

You could grow Lantana around the perimeter of your fence. Or you could try deer spray (a lot like the pepper spray GhettoGardner discussed, but also has putrified egg solids and sometimes garlic.) Or you could trap them and eat them! Connie stew, anyone?