A chemical repellent is registered in Kentucky for use on edible crops. The key ingredient is 15% ammonium soaps of higher fatty acids. You can spray it on plants in the garden, including things you might eat. It must be applied every 2-4 weeks and after any rain. Thiram and bone tar oil are other active ingredients in commercial deer repellents.  With that in mind, it might cost less to put up a fence.