White-tailed deer are classified as concentrate selectors, meaning they are highly selective browsers rather than grazers like cattle. These animals actively seek out plants that are easily digestible and packed with nutrients, such as protein, fat, and oil. Their specialized digestive system, including a relatively small rumen, is best suited for consuming high-quality, low-fiber vegetation. This preference drives their opportunistic feeding habits, and their diet fluctuates based on local habitat, seasonal availability, and immediate nutritional requirements.
Highly Preferred Plants and Palatability
Deer are drawn to plants that offer high moisture content and minimal physical or chemical defenses. The highest palatability is assigned to tender, succulent vegetation that is easy to bite off and requires little chewing before swallowing. This preference explains why ornamental garden favorites are often the first to be targeted in residential areas.
Common garden plants like hostas and daylilies are particularly vulnerable, prized for their large, soft leaves and high water content. Flowering bulbs, such as tulips, are considered a delicacy, and deer will often consume the entire flower and bud. In the vegetable garden, high-protein crops are aggressively sought out, including peas, beans, lettuces, and clover.
Cultivated plants are often irresistible, especially those that have been fertilized, which boosts their protein and mineral content. Young fruit trees, including apple and cherry saplings, are frequently browsed because their new growth is soft and rich in sugars. Landscape shrubs like arborvitae and yew are also heavily favored, often becoming a primary food source when other options are scarce.
The Role of Seasonal Forage and Browse
A deer’s diet shifts dramatically throughout the year to meet the changing demands of its life cycle and the environment. During spring and summer, the focus is on high-protein forage to support lactation in does and rapid antler growth in bucks. This diet consists largely of forbs, which are herbaceous, non-woody plants like wildflowers and certain weeds.
Tender forbs such as wild lettuce and pokeweed are selected because they can boast crude protein values well over 13%, fueling the intense summer growth period. As the season progresses into fall, the diet transitions toward calorie-dense foods necessary for building fat reserves for the upcoming winter. Hard mast, primarily acorns, becomes a major food source due to its high concentration of fats and oils.
In the winter, when soft vegetation is dormant or covered by snow, deer rely heavily on browse, defined as the twigs, buds, and woody stems of trees and shrubs. Woody browse from species like honeysuckle and sumac provides a stable, though less nutritious, foundation for survival. While the nutritional quality of winter browse is lower than summer forage, it provides the bulk necessary to sustain the animal until new growth emerges in spring.
Plants Deer Usually Leave Alone
Deer avoid plants possessing characteristics that interfere with their feeding efficiency or digestive comfort. Strong aromatic foliage is a common deterrent, as the pungent oils and odors found in plants like rosemary, Russian sage, and members of the mint family are unappealing to their sensitive sense of smell. These compounds often signal a bitter taste or the presence of defensive chemicals.
Plants with challenging textures are also frequently bypassed, including those with fuzzy or hairy leaves, such as lamb’s ear and butterfly bush. The tough, leathery texture of certain leaves, or the presence of spines and thorns, makes them uncomfortable to chew and digest. Mahonia and barberry are examples of spiny shrubs that deer tend to leave alone.
Many plants contain toxic or bitter compounds that act as a natural defense mechanism against browsing. The alkaloids in plants like yew and boxwood give them a highly bitter taste, while bulbs like daffodils contain poisonous compounds. While no plant is completely immune if a deer is desperate, these qualities make them a low-priority option.