Woodchucks, also known as groundhogs (Marmota monax), are overwhelmingly herbivorous, feeding on a wide range of grasses, clover, wildflowers, and garden vegetables. Their diet shifts across the seasons in ways that mirror their famous hibernation cycle, and they occasionally surprise people by snacking on insects or other small animals. The specifics of what they eat, when they eat it, and how much they consume make woodchuck feeding ecology more interesting than their reputation as simple garden pests might suggest.
The Core of a Woodchuck’s Diet
Woodchucks are grazers and browsers that rely heavily on green, leafy vegetation. The foundation of their diet includes common plants that grow in the open meadows, field edges, and transitional habitats they prefer: clover, alfalfa, dandelions, plantain, and various wild grasses. They also eat the leaves, stems, and flowers of a wide variety of herbaceous plants found in their home range, including goldenrod, asters, and chickweed. Unlike some rodents that depend heavily on seeds and nuts, woodchucks show a clear preference for soft, succulent plant tissue. They are leaf eaters at heart.
Fruits and berries round out the plant-based menu. Woodchucks will eat wild strawberries, blackberries, and cherries when they find them, and they readily consume apples and other tree fruits that fall within reach. They don’t typically climb trees to forage, though they can climb if motivated, so most fruit eating happens at or near ground level. Bark, twigs, and woody material play a minor role, mostly in early spring when green plants are still scarce.
How Diet Changes Through the Seasons
Woodchuck eating behavior is tightly linked to their hibernation cycle, which creates dramatic seasonal shifts in how much and what they eat. They emerge from hibernation in late winter or early spring, often before much fresh vegetation is available. During this lean period, they may nibble on bark, buds, and whatever early shoots they can find. Their appetite at emergence is modest compared to what comes later, partly because their digestive systems need time to ramp back up after months of dormancy.
As spring progresses and fresh growth appears, feeding intensity climbs. Woodchucks become active grazers, spending much of their above-ground time eating. By midsummer, they are feeding heavily on the full range of available vegetation, and their body weight increases steadily. This buildup of fat reserves is the whole biological point of their active season. A woodchuck needs to roughly double its spring body weight before entering hibernation in the fall, and that requires sustained, aggressive feeding through the warmest months.
By late summer and into early fall, woodchucks are at peak consumption. They favor calorie-dense plant material during this period, showing a preference for fruits, agricultural crops, and the richest forage they can find. Once they enter hibernation, typically in October or November depending on latitude, they stop eating entirely and survive on stored body fat until the cycle begins again. This feast-or-fast rhythm is one of the most extreme of any North American mammal.
The Garden Pest Problem
Woodchucks have earned a notorious reputation among gardeners and small-scale farmers, and the reason is straightforward: many of the plants they prefer most are exactly what humans grow. Beans, peas, lettuce, broccoli, cabbage, carrots, squash, and corn are all fair game. Woodchucks can devastate a vegetable garden in a few visits, and because they tend to eat plants down to the stem rather than nibbling selectively, the damage is often total rather than cosmetic.
Flower gardens are not spared either. Woodchucks eat marigolds, sunflowers, daylilies, and many other ornamental plants. They seem to have genuine preferences, consistently targeting some species while ignoring others in the same garden. Experienced gardeners in woodchuck territory learn quickly that certain crops need protection while others are left alone. Herbs with strong scents, like lavender and mint, are usually low on their list, while tender legumes and brassicas are almost irresistible.
The damage woodchucks cause goes beyond eating. Their burrow systems, which can extend twenty feet or more with multiple entrances, undermine foundations, disrupt drainage, and create tripping hazards. But the dietary conflict is what brings most homeowners into direct contact with woodchuck behavior. A single adult woodchuck living near a garden can consume several pounds of vegetation per day during peak summer feeding.
Opportunistic Animal Foods
Despite being classified as herbivores, woodchucks are technically omnivorous. They occasionally eat insects, grubs, snails, and other small invertebrates they encounter while foraging. This behavior is well documented but represents a very small fraction of their overall diet. Some researchers have also observed woodchucks eating bird eggs and even nestlings on rare occasions, though this seems to be genuinely uncommon rather than a regular part of their feeding strategy.
The animal-based component of their diet is probably best understood as opportunistic rather than intentional. A woodchuck grazing through a meadow may encounter a grasshopper or a beetle and eat it without going out of its way to hunt. Insects may also provide a small protein boost during the critical fat-building period before hibernation. But no one studying woodchucks would describe them as predators in any meaningful sense. Their teeth, digestive system, and foraging behavior are all adapted to processing plant material, and that is what they eat the vast majority of the time.
How Woodchucks Forage
Woodchucks are diurnal, doing most of their feeding during the morning and late afternoon. They rarely stray far from their burrow entrances while foraging, typically staying within a hundred yards or so of a known escape route. This cautious foraging pattern means they tend to eat whatever grows closest to home rather than ranging widely in search of preferred foods. It also explains why a woodchuck that establishes a burrow near a garden will return to that garden repeatedly. The food is close, and the burrow is right there.
Their foraging posture is distinctive. Woodchucks sit upright frequently while eating, scanning for predators between bites. Hawks, foxes, coyotes, and domestic dogs all pose threats, so a woodchuck at a feeding site is always balancing caloric intake against vigilance. They tend to eat quickly and efficiently, clipping vegetation with their incisors and chewing rapidly before swallowing. Unlike some herbivores that chew cud or have complex multi-chambered stomachs, woodchucks have a relatively simple digestive tract and process food in a single pass. This means they need to eat a high volume of plant material to extract enough nutrition, which partly explains why they spend so much of their waking time feeding.
Woodchucks don’t cache or store food. Every calorie they consume goes directly into their body. This is a major difference from squirrels and chipmunks, which stash nuts and seeds for later use. Because woodchucks rely entirely on body fat to survive hibernation rather than stored food, they have no reason to hoard. What they eat today becomes the fat that keeps them alive next February.
Urban and Suburban Woodchucks
Woodchucks are remarkably adaptable animals, and their diet reflects whatever landscape they happen to occupy. In rural areas, they feed primarily on pasture grasses, hay crops, wild plants, and the edges of agricultural fields. Alfalfa fields are particularly attractive to them, and farmers in the eastern United States have long considered woodchucks a nuisance for the damage they do to hay and forage crops.
In suburban and even urban settings, woodchucks adjust their diet to take advantage of what’s available. Residential gardens, landscaping plants, and even lawn grass become primary food sources. Suburban woodchucks may eat a wider variety of cultivated ornamental plants than their rural counterparts simply because that’s what grows around them. There’s some evidence that woodchucks living closer to human development can maintain comparable body condition to those in more natural settings, which suggests they’re getting adequate nutrition from the hodgepodge of suburban vegetation available to them.1The American Midland Naturalist. Survival, Habitat Selection, and Body Condition of the Woodchuck (Marmota monax) across an Urban-Rural Gradient
Golf courses, cemeteries, parks, and highway medians all provide habitat for suburban woodchucks. These settings offer the combination of open grassy areas for feeding and soft soil for burrowing that woodchucks need. The diet in these habitats is essentially whatever ground-level vegetation is present, from Kentucky bluegrass on a golf course to ornamental hostas beside a walking path.
What Woodchucks Don’t Eat
Understanding what woodchucks avoid can be just as useful as knowing what they prefer, especially if you’re trying to coexist with one. Woodchucks generally leave strongly aromatic herbs alone. Rosemary, thyme, oregano, sage, and lavender are all low-preference foods. They also tend to avoid plants in the allium family, including garlic, onions, and chives, though individual woodchucks may surprise you.
Toxic plants are usually avoided as well. Woodchucks steer clear of rhubarb leaves, daffodils, and foxglove, among others. They seem to have a reasonably good instinct for avoiding plants that would make them sick, though this isn’t foolproof. Very hungry woodchucks emerging from hibernation may sample plants they would normally ignore.
They also aren’t interested in most seeds and grains in the way that mice, rats, and squirrels are. While a woodchuck might eat an ear of corn on the stalk, it’s unlikely to break into a bird feeder or raid a grain bin. Their dietary niche is firmly in the “fresh green vegetation” category, which separates them from many of the other common backyard rodents people deal with.
Keeping Woodchucks Out of Your Garden
If you’re dealing with a woodchuck that has discovered your vegetable patch, fencing is the most effective deterrent. But standard garden fencing often fails because woodchucks are both diggers and climbers. A fence that works needs to extend at least a foot underground, bent outward in an L-shape at the bottom, and stand at least three to four feet above ground. Leaving the top foot of fencing unsupported so it flops outward can prevent climbing, since woodchucks struggle to scale a surface that bends away from them as they ascend.
Planting a border of strongly scented herbs around a garden provides a mild deterrent but is rarely sufficient on its own. Some gardeners report success with commercial repellents based on capsaicin or predator urine, though these need frequent reapplication and tend to be less effective than physical barriers. Motion-activated sprinklers can startle woodchucks away from specific areas but lose effectiveness over time as the animals habituate.
Removing brush piles, rock walls, and other attractive burrowing sites near the garden can also help by making the area less hospitable. Woodchucks are creatures of convenience. If they have to travel far from their burrow to reach your tomatoes, they’re more likely to eat something closer to home instead. Encouraging them to set up their burrow elsewhere on your property, rather than right beside the raised beds, is sometimes the most practical approach.
How Woodchuck Diet Compares to Other Marmots
Woodchucks belong to the marmot genus, a group of large ground squirrels found across North America, Europe, and Asia. Among marmots, the woodchuck’s diet is fairly typical in its reliance on herbaceous vegetation, but its habitat is unusual. Most marmot species live in alpine or steppe environments where plant diversity is limited and the growing season is short. The woodchuck, by contrast, occupies lowland forests, farmland, and suburban areas across the eastern half of North America, giving it access to a much broader menu of plants.
This ecological flexibility is part of why woodchucks are so successful and so widespread. They don’t depend on any single plant species or plant community. Drop a woodchuck into a hay field, a suburban backyard, a forest clearing, or a highway median, and it will find something to eat. That dietary generalism, combined with their ability to hibernate through the months when food is unavailable, makes them one of the most resilient rodents on the continent. Their willingness to eat practically any green, leafy plant they encounter is both the key to their ecological success and the reason they’ll always be showing up in someone’s garden.
Water and Hydration
One common question about woodchuck feeding is whether they need to drink water. The answer is that they get most of their moisture from the vegetation they eat. Fresh, succulent plant tissue has a high water content, and woodchucks consuming large volumes of leafy greens, fruits, and clover are taking in substantial water with every meal. They will drink from puddles, streams, or other water sources when available, but they don’t depend on standing water the way many mammals do. This is part of why they can thrive in areas without permanent water nearby, including dry hillsides, highway shoulders, and well-drained suburban yards where the closest stream may be hundreds of yards away.
During the buildup to hibernation, when woodchucks are eating the most, their water intake from food alone is considerable. By the time they enter their burrows for winter, their bodies are carrying enough stored fat and metabolic water reserves to sustain them through months of dormancy without eating or drinking at all. The entire system, from what they eat, to how much, to when they stop, is engineered around surviving a long winter underground on nothing but what their body has stored.