I find it is all seasonal. In the coldest days of winter when absolutely nothing is left they will eat all kinds of things they leave alone the rest of the year promise.If you care to listen to a few guys who address these problems for a living.Deer Control Podcast http://recordings.talkshoe.com/TC-16456/TS-182185.mp3
Here is a podcast we did on Jan 16, 2009 on this topic.
Mike Flick the host,of owner of Anytime Animal Control operates 28 offices, found in eight states, California, Connecticut, Florida, Illinois, Mississippi, Missouri, New York,and in Wisconsin.
Mike offers consumers free tips they can do on their own to prevent deer damage each winter.
Food for deer become quite scarce as they like other animals compete with other species for food to graze on. As seasons change, the preferred food sources of deer change as well. The evergreen shrubs that the deer ignored while they were munching on your leafy garden in the summer months suddenly look pretty appealing in the late fall and winter when most plants have either dropped their leaves or disappeared by going dormant or dying. Deer develop new browsing trails as food sources change with the seasons, and repeatedly follow them through the season until new food sources begin to appear.
The most effective solution is fencing, and it has to be high, eight feet or more. For those of you with severe deer feeding pressure, this is probably your only real choice.There are repellents on the market but many of them are often impractical .