The simplest, cheapest and most environmentally safe repellant for ALL herbavores is a carnivore's urine.

If you eat meat, the answer is simple drink a couple glasses of water a there you are instant deer repellant. Capture some urine and pour it around the perimeter of your garden and ALL herbavores (and the lesser omnivores) will be repelled by it.

All carnivores mark their territory, and that's what you need to do as well. To remain effective, you must reapply the urine every couple of days particularly after rain.

Good luck on your garden.