Go to an outdoors or hunting store and get some Red Fox Urine. Spray this around your plants and the deer will think there is a predator nearby. It doesn't last all that long so after a few rains you will need to re-apply it in the area of your grow. There are also many deer and rabbit repellants on the market for gardens which may or may not work, they are meant more for small flower gardens or vegetable gardens. I've used the urine scent before and it works, depending on how big an area your grow is.