Deer are herbivores, which means that they primarily eat plants, ivy and grass. Many deer, especially whitetail deer, eat acorns that fall from trees, as well as hickory nuts, beechnuts and pecans.
When available, deer also enjoy eating fruit, such as apples and persimmons. These types of food aren't readily available for deer to consume, however, so they don't make up a large part of a deer's diet.
Deer often travel towards areas where food is plentiful, such as forests and meadows. In areas such as these, they have a larger access to dandelions and wild roses. When food becomes scarce in the winter, deer adapt to the weather by migrating towards more survivable areas and fattening up throughout autumn to prepare for the shortage. Deer also depend on fallen leaves and twigs to survive during the rougher seasons. Even when the food supply is very low, they can typically survive for a few weeks based on their stored fat and lowered metabolism.
Farmers and gardeners typically aren't fond of deer, as they pose a threat to newly grown crops. Deer are known to scavenge for beans, potatoes, soybeans, wheat, sweet potatoes and rye, and usually steal crops from the edge of a farmer's plot, so that they can escape quickly if they sense that they've been spotted.