With a streambank restoration, we generally protect several plants within a small area. We surround the entire area with mesh fencing. Volunteers hammer several five foot tall stakes into the ground, about one foot deep, around the planted area and tie mesh fencing to the stakes with zip ties (a.k.a., cable ties), making sure that the protection reaches the ground and is not sagging between stakes. Be sure to check the fencing every week or so to see if there has been any damage to the fence or if any small animals are caught in the fencing.
Chemical repellants are also available. However, application of these repellants can be time consuming and deer can become accustomed to them after time. In addition, they frequently wash off the plants in the rain.