If groundhogs are eating up your garden, it's critical to learn the best ways to rid your yard of these pests. Begin by learning exactly what groundhogs are, how they live, and what signs to be on the lookout for in order to detect their presence as soon as possible.
What Exactly Are Groundhogs and How Do They Live?
Groundhogs, or "woodchucks" (Marmota monax) are rodents indigenous to the eastern U.S. and are most often found where a wooded area meets a clearing.
Their burrows, in which groundhogs spend most of their time, can be 50 feet long. Groundhogs hibernate in winter, during which time they do not stir from their burrows. The same den is also used for mating (which occurs just after hibernation ends) and raising young. A woodchuck burrow will often have one main entrance and one emergency escape entrance or spy-hole. In summer and fall, the den is where groundhogs sleep at night and hide from predators.
Detecting the Presence of Groundhogs, and What They Eat
Some good indicators of a groundhog's presence are:
- A hole 10 to 12 inches wide in the ground or under your outdoor storage shed with mounds of dirt outside it.
- A tomato with a good-sized bite taken out of it.
- The feathery tops of your carrots have been mowed down.
Besides the damage woodchucks cause to plants, they are sometimes responsible for other kinds of harm:
- They can undermine sheds, foundations, driveways, and retaining walls.
- They can hurt a dog in a fight.
- You could twist an ankle by accidentally stepping into a woodchuck hole.
Some animals, such as deer pests, will eat up your garden during the nighttime, but groundhogs do most of their eating in the early morning and early evening. They eat a wide variety of garden vegetables. They can climb trees, so even the fruit in your fruit trees is not safe.
How to Get Rid of Groundhogs
Fumigation and shooting are options best reserved for rural settings. Other gardeners should consider these control solutions:
- Scaring and repelling groundhogs
- Fencing and floating row covers
Preventing Groundhog Infestations
To reduce the chances of attracting groundhogs, make depriving them of areas with tall grass, tall weeds such as Japanese knotweed, overgrown shrubs, and brush piles part of your landscape maintenance. These will only serve as hideouts for groundhogs. Better yet, clear such areas altogether and start a new garden. Groundhogs eat dandelions and clover, so keeping your grass free of these common lawn weeds reduces your chances of attracting groundhogs.
Fill in any old tunnels with crushed stone; otherwise, you're rolling out the welcome mat for new pests. Since groundhogs are rodents, remove any tree stumps (rodents need a source of wood to grind their continually growing incisor teeth upon).
Scaring and Repelling Groundhogs
The concept here is you can frighten groundhogs away by exploiting:
- Foul tastes
- Foul smells
Epsom salts can be sprinkled on the leaves and fruits of garden plants to render them foul-tasting to groundhogs (but not to you). Epsom salts also help some plants grow better. Ammonia-soaked rags strewn along the garden perimeter form a stinky barrier, but rain washes away both these smells, necessitating reapplication.
You can buy repellents at farmer's supply stores. Some even have success with kitty litter because of the urine smell it contains (cats being predators). Commercial repellents come in both granular and liquid form and also must be reapplied after it rains. Read directions carefully because one product can be quite different from another. Granular repellents are based on smell: Pour them right into woodchuck burrows and all around the openings. Liquid repellents drive groundhogs away with their taste, instead. Apply them around the garden but not directly onto something that you will be eating, because you won't like the taste, either.
Use motion-detector devices such as the Scarecrow Sprinkler. After detecting motion, it sprays water at the offender, causing it to flee.
Keeping Groundhogs Away With Row Covers and Fencing
Here, the idea is to deny the pests access to your garden. Applying floating row covers on top of your crops has the added benefit of excluding insect pests.
Fences such as chicken-wire fences provide a more permanent solution. Be aware of two factors; groundhogs can climb over and tunnel under fences. To discourage the former, make your fences 3 to 4 feet high, and leave the top foot of chicken wire unattached to the posts. Bend this uppermost foot outwards—rather like for prison fencing. To foil tunneling attempts, the University of Missouri Extension advises:
"The buried portion of the fence should be bent at a 90-degree angle, 1 foot below the surface, with the bottom of the fence pointing away from the garden. This design discourages burrowing if it is started at the fence line."
Such a fence can be supplemented with an electric hot-shot wire. Install the wire 4 to 5 inches away from the fence, all along the outside. The electric wire should stand 4 to 5 inches high.
Live Traps and When to Trap Groundhogs
Various traps are used to catch groundhogs, as well as in rabbit control, vole control, etc., but gardeners are interested mainly in the types considered humane, rather than in lethal (body-grip) traps. Live-trapping has the advantage of being permanent, without your having to kill the pests. The key to its effectiveness is relocating the groundhogs at least 5 miles away from your garden.
It has three drawbacks:
- Relocation is illegal in some states.
- Finding an acceptable relocation destination can be problematic. One option is to find an animal-loving landowner who wouldn't mind having a resident groundhog. As long as you get permission first, you could also consider a state wildlife management area.
- While more humane than killing animals outright, relocation isn't entirely humane: Many relocated animals fail to adapt and end up dying in their new homes.
A live trap, such as Havahart's, is a wire box with door(s) and a tripping mechanism. The tripping mechanism is baited, and the door(s) rigged so as to close behind the unwitting prey, caught red-pawed over the tripping mechanism.
Late winter/early spring is the best time for trapping groundhogs. The groundhogs alive in early spring are the adults that will produce the next generation later in the spring. Catching one in March could mean eliminating five in June. Early trapping also has tactical advantages, because the landscape is barren:
- It's easier to locate burrows.
- Groundhogs will be more desperate for food. Your bait will be more irresistible than in June when there's plenty of food. Bait your trap with lettuce, peas, etc.
How to Trap Groundhogs
Place your trap just outside the burrow—at most 5 to 10 feet away from it. Installing guide logs at either side of the path between the burrow and the trap will help funnel the groundhog in. Hide the trap with vegetation. Havahart recommends sullying a new trap to divest it of its gleam and smell. Wear gloves when setting it up to eliminate human scent.
If trapping in summer, when groundhogs can afford to be choosier about bait, purchase a product called "woodchuck lure." Sprinkle drops of it in a path from the burrow to the trap, enticing the pest in. Apply additional drops of the lure to the bait itself.
When you release the animal, exercise caution: It is now agitated, its actions won't be predictable, and its sharp teeth can deliver a serious bite.