Feeding Habits
Deer are herbivores. That means that they only eat plants, not meat. As such, they are not hunters; they wander along well-known trails and paths to areas where they have found food before. They generally eat during morning and late afternoon when most hunters have success finding them. Deer diet changes depending on seasons. They will consume green vegetables such as cabbage, lettuce and corn during spring and summer and then depend on nuts and twigs through fall and winter.
Crops
Deer will eat crops every time they get the chance. It cannot be overstated how important cultivated crops are to a deer's diet. Most of the time, deer eat cultivated grasses and corn, but will not hesitate to eat any other crop in commercial production if they are hungry. Deer are a bigger problem for gardeners than for farmers, because a deer can wipe out an entire garden in one morning, whereas farmers will usually see signs of deer foraging and be able to stop them before they ruin the crops.
Gardens
While agricultural crops do make up a lot of the deer's diet, it does not mean that home gardens are safe from the herbivore. In fact, if a deer finds out that your garden is full of green vegetables, it will eat them. Certain vegetables are less attractive to deer, but a hungry dear will eat any type of vegetable that it comes across, even the traditional repellents: onions and garlic.
Feeding or Preventing
If you wish to feed deer from your garden, plant corn, grasses, cabbage, lettuce, carrots or other types of veggies. These are not elusive creatures if you have the right kind of food. However, if you are trying to prevent deer munching, plant the outskirts of your garden with rosemary, garlic and onions and run a white rope or hang white socks that can flap in the wind around the garden. White signals danger to whitetail deer (they flash their white tails in danger situations). Also, fencing, especially electric fencing, can keep deer out. Alternatively, if law permits, set up a hunting stand, and you can harvest meat and veggies from your garden.