Groundhogs, also known as woodchucks, are common across North America and are frequently considered a major nuisance by gardeners. They are avid herbivores that consume vegetation during warmer months to build fat reserves for hibernation. Groundhogs definitively eat lettuce; this soft, water-rich leafy green is one of their most favored food sources. This preference extends to a wide array of cultivated crops, making the groundhog an efficient garden pest.
Understanding the Groundhog’s Natural Diet
The groundhog is a member of the marmot family and is classified as a true hibernator. Its survival depends on consuming large quantities of food throughout the spring and summer. Their natural diet primarily consists of wild, low-lying vegetation such as clover, alfalfa, and dandelions, which are high in protein and moisture content.
They emerge in the spring with an energy deficit and a metabolic system primed for rapid weight gain. This intense seasonal cycle requires a dramatic increase in food intake. An adult groundhog can consume over a pound of vegetation in a single day, driven by the need to double their body weight before hibernation in the late fall.
Commonly Targeted Garden Vegetables
The cultivated garden is an easily accessible and highly appealing food source, richer than wild forage. Garden vegetables often possess higher water content and greater concentrations of simple sugars, making them more palatable and easier to digest. This nutritional superiority draws groundhogs directly to backyard plots, often resulting in swift damage.
Groundhogs frequently target leafy greens like lettuce, cabbage, kale, and broccoli, sometimes gnawing them down to the stem. They also relish legumes, with entire rows of young bean and pea plants often disappearing overnight. Damage is characterized by the complete destruction of plants, as groundhogs are voracious feeders once they gain access.
Later in the season, as the animals prepare for hibernation, their diet shifts to include fruits and high-calorie produce from the cucurbit family. This includes the vines and fruit of squash, zucchini, and melons, which provide a final surge of energy-dense food. Groundhogs also feed on the tops of carrots and the stalks of celery.
Effective Methods for Deterrence
The most effective strategy for protecting a garden from groundhogs involves exclusion through physical barriers, as the animals are persistent diggers and climbers. An ideal garden fence should stand at least three feet high to discourage climbing, and it must be constructed from heavy-gauge galvanized wire mesh. Avoid using lightweight chicken wire, which groundhogs can easily chew through.
To prevent burrowing underneath, the fence requires an L-shaped barrier, sometimes called an L-footer. This barrier involves bending the bottom of the wire at a 90-degree angle. The vertical section should be buried 10 to 12 inches deep, and the horizontal section should extend outward for at least a foot. When the groundhog attempts to dig under the fence, it encounters this buried, outward-facing wire apron, which physically frustrates the digging attempt.
Repellents and habitat modification offer supplementary protection but are generally not effective on their own. Strong scents, such as those from castor oil or garlic-based sprays, can be applied near burrows or along the perimeter, potentially deterring the animal’s sensitive sense of smell. Additionally, removing nearby brush piles, wood stacks, or dense ground cover eliminates potential secondary den sites, making the area less hospitable to a groundhog seeking shelter.