Over the winter deer can devastate ornamental plantings like arborvitae, rhododendron, boxwood and holly. We apply Deer Pro up to deer browsing height to make the plant tissue have a bitter taste. Deer tend to feed on preferred sources over and over so only light sampling will occur and the deer will feed on other, tastier, plants. The light green color at the bottom of the pictured arborvitae is the treated area. It lasts all winter, has anti-dessicant properties to protect the plant from winter burn as well and will weather off with the spring rains.