Milorganite works well for me. And it is beneficial to feed the plants. Needs to be reapplied. However, Milorganite alone doesn't do it for me. Last year I put up metal posts with pie tins tied to them (the cheap ones that you get from frozen pies). They fly in the wind and bang on the posts. Little unsightly, quite noisy at times AND the deer do get used to them eventually. I think whatever is used, it needs to be changed up throughout the year. The deer are smart and can decide when something really isn't a threat to them after all.
