The problem is that groundhogs—also known as woodchucks or whistle-pigs—are binge eaters who can wipe out your vegetable garden in a matter of minutes. They climb, they burrow, they swim, and they eat—an adult consumes about a pound to a pound-and-a-half of vegetation daily. Between spring and fall, they double their body weight.
Do Groundhogs Hibernate?
Yes, they do! Soon after they emerge from a winter’s hibernation, they mate, giving birth in mid-spring—at a time when the picking are at their slimmest. Neat rows of seedlings must look like manna from heaven to hungry groundhogs, who sometimes perch on garden fence posts as if they are looking over the salad bar.
When hibernating, groundhogs—who are never speedy—really slow down, drawing a breath only about once every five minutes. Hibernation is curious behavior: Barely breathing, these mammals cool off to just a few degrees above the ambient temperature, sometimes as low as 39º to 40ºF. Their metabolic rate drops, and they sleep profoundly in their winter dens, neither eating nor drinking for four-and-a-half to five-and-a-half months, drawing all their nourishment from the body fat they accumulated during the summer. No wonder they eat so much!
How to Identify Groundhogs
Members of the squirrel family, groundhogs are squarish, stocky animals that typically weigh between 4 and 14 pounds. The have short, strong legs; coarse, grizzled, gray-brown fur; small ears; a short, bushy tail; and curved claws. Groundhogs look a bit like runaway fur coats as they waddle back to their burrows. This critter can grow to be about 3 feet long. They have large, competent, chisel-like teeth that make them efficient, but not quite endearing.
Wondering where groundhogs live? See any deep tunnels in your yard, under your deck, or near your foundation? You may have a groundhog; they dig burrows to live in and the entrances are usually 10 to 12 inches wide with the excavated soil spread around the entrances. There are usually 2 or 3 entrances.
What do groundhogs eat? Everything from flowers to vegetables. Favorite foods include alfalfa, clover, peas, beans, lettuce, broccoli, plantain, and soybeans. Groundhogs will often devour your seedlings before they even have time to grow. Rabbits and deer eat some of the same plants, so make sure to check for burrows before concluding that you have groundhogs. If you don’t have vegetables around, groundhogs will settle for twigs, bark, bugs, and blossoms.
Groundhogs eat mostly during the early morning and afternoon, so try to see when your garden is receiving the most damage. These creatures will also gnaw and claw at fruit trees, so check your trees for any such marks.
Control and Prevention
How to Get Rid of Groundhogs
These critters may have been attracted by your garden full of tasty plants. Encourage them to go elsewhere.
Sprinkle blood meal, ground black pepper, dried blood, or talcum powder around the perimeter of your garden. You can try using hair clippings as well.
Puree and strain hot peppers and garlic, mix them with water and enough liquid soap to make it stick, and spray it liberally around the garden.
Put some harmless but strong-smelling substance just inside the burrow (such as urine-saturated clumps of kitty litter). Loosely seal the entrance, so the smell stays inside the burrow.
Would you eat lettuce tossed with bobcat urine? Neither would a woodchuck! Fox, coyote, wolf, and bobcat urines are among the forbidding predator scents now sold as groundhog repellents.
Eliminate woodpiles and other places where groundhogs nest.
Keep undergrowth and grass cover low to deter groundhogs.
Groundhogs are always looking for vacant burrows. Close down their tunnel systems. Bury a three-foot-square panel of welded wire, centered over the entrance hole before an abandoned burrow is rediscovered.
Unfortunately, humane traps and relocation may be the only solution. Place traps in front of burrow entrances or in the garden. Bait them with broccoli, apple slices, fresh lettuce, carrots, or sweet corn, and work the bottom of the trap into the earth. Check the trap often after setting it to minimize stress and injury to trapped creatures. Cover the trap with an old blanket to calm the groundhog.
How to Prevent Groundhogs from Invading Your Garden
The best woodchuck deterrent is a fence. Excluding woodchucks from the garden will also keep out deer, rabbits, raccoons, and stray pets. Since groundhogs climb and also burrow, you’ll need to build a secure enclosure using six-foot-wide woven-wire fencing. Above ground, the fence should be about four feet high, with the top 12 inches unattached to fence posts (i.e., floppy and facing away from the garden, so that when a groundhog tries to go over the top, its weight will flip it back). The two feet of fencing buried underground should form an L-shape, with 12 inches going straight down and the bottom 12 inches bent at a right angle away from the garden.
An apron of weighed-down black plastic around the garden discourages some diggers, as does an electric fence strung four to six inches off the ground about four to six inches outside the woven-wire fence.
Pay special attention to areas facing fields where woodchucks live or places where they have been digging; sometimes extra fortification in just these spots is called for. Be sure the gate is protected, too. Fencing is not inexpensive, but it’s an investment in serious gardening.