Deer are primarily herbivorous, but their feeding habits are highly opportunistic, consuming a variety of foods depending on availability and environmental stress. Deer are generally classified as browsers, selecting high-quality forage like young leaves, tender shoots, and fruits over coarse grasses. This dietary flexibility means a deer’s food choice often comes down to what is most accessible. The potato plant presents an interesting target, offering both relatively unappetizing foliage and a starchy, energy-dense tuber.
Preference and Consumption of Potato Tubers
Potatoes are not a preferred natural food source for deer and are considered less desirable than options like sweet potato vines, peas, or spinach. The tubers grow underground, which physically protects them from easy browsing. Deer prefer meals that require minimal effort, making digging up potatoes more work than grazing on leaves.
Consumption changes when other food sources become scarce, such as during severe winters or prolonged drought. In these stressful conditions, deer become less selective and will consume the potato plant’s foliage (leaves and stems). A hungry deer will sometimes even dig to access the buried, carbohydrate-rich tubers. If harvested potatoes are left exposed on the surface, deer will consume them readily due to their easy accessibility and high caloric content.
Nutritional Considerations and Plant Toxicity
The potato plant (Solanum tuberosum) belongs to the nightshade family, which contains protective chemical compounds known as glycoalkaloids. The primary glycoalkaloid is solanine, which acts as a natural defense mechanism against insects and herbivores. Solanine has a bitter taste that generally discourages deer from consuming large quantities of the foliage.
The concentration of these toxins varies significantly across the plant; the leaves, stems, flowers, and any green parts of the tuber contain the highest levels. While the white, fully developed tuber has low, safe levels of solanine, exposure to light causes the tuber to turn green and dramatically increase its solanine content. Consumption of these high-alkaloid parts can cause symptoms in mammals ranging from digestive upset to neurological issues. The tuber’s high starch content provides energy, but this benefit comes with the inherent risk of toxicity.
Strategies for Protecting Potato Crops
The most effective method for protecting potato patches from deer is installing physical barriers. Since deer are capable jumpers, a standard fence must be at least eight feet tall. Alternatively, a double-layer fence spaced several feet apart is effective, as it confuses the deer’s depth perception and discourages jumping.
Sensory deterrents offer a secondary layer of protection by making the plants unappealing. Commercial repellents often use foul smells or tastes, such as spicy pepper solutions or rotten egg solids, applied directly to the foliage. Motion-activated devices, like sprinklers or ultrasonic sound emitters, capitalize on a deer’s tendency to be easily startled. To maintain effectiveness, gardeners should rotate different types of repellents to prevent the deer from becoming accustomed to a single deterrent.