A woodchuck eats plants. It eats a great many plants, with particular enthusiasm for the ones somebody has carefully planted in rows and intends to eat themselves.
The everyday diet
Grasses, clover, alfalfa, dandelions, plantain and similar soft green growth make up the bulk of what a woodchuck eats. It is a grazer, working through low vegetation close to a burrow entrance rather than foraging widely.
It will occasionally take insects, and there are scattered reports of other small items, but these are incidental. A woodchuck is a herbivore in practice as well as in principle.
Why gardens are irresistible
A vegetable garden is, from a woodchuck's perspective, a meadow that somebody has improved considerably. The plants are soft, densely planted, well watered, free of competition and conveniently arranged.
Beans, peas, lettuce, squash and young brassicas are common casualties. The damage tends to arrive suddenly, because a woodchuck that finds a productive patch will return to it repeatedly rather than moving on.
The autumn binge
Appetite is not constant through the year. From late summer into autumn a woodchuck eats heavily and steadily, building the fat reserves that must sustain it through months of hibernation.
This is when gardeners notice them most, and when the animal reaches its heaviest weight of the year. By spring emergence the same woodchuck may be dramatically lighter, having burned through the lot while asleep.
What it does not eat
Wood. It bears repeating in an article about diet: the woodchuck does not eat wood, and does not chuck it either.
It gnaws wood, because rodent incisors grow continuously and must be worn down. But bark and timber are dental equipment, not food. Nothing about the woodchuck's digestive arrangement is built for it.
Frequently asked
What do woodchucks eat?
Almost entirely soft green plants - grasses, clover, alfalfa, dandelions and similar low vegetation - supplemented enthusiastically by garden vegetables such as beans, peas, lettuce and squash. Insects are taken only incidentally.
Do woodchucks eat wood?
No. Woodchucks gnaw on bark and timber to wear down their continuously growing incisors, but wood is not part of their diet. They are herbivores that feed on soft green vegetation.
When do woodchucks eat the most?
From late summer into autumn, when they feed heavily to build the fat reserves needed to survive months of hibernation. This is when they reach their heaviest weight and when garden damage is most noticeable.