Groundhogs (also called woodchucks) look harmless, but a single animal can excavate burrows up to 25 feet long, collapse raised beds, undermine foundations, and devour an entire vegetable garden overnight. This guide covers the 10 best methods to get rid of groundhogs humanely and permanently, ranked from most to least effective.
Key Takeaways
- A properly installed woodchuck fence is the most reliable long-term solution
- The best eviction window is mid-to-late summer (July–September) before groundhogs den up for winter
- Castor oil repellent is the most effective chemical-free deterrent — apply every 2 weeks
- Gas bombs are inhumane, often illegal, and less effective than non-lethal methods
- Combining fencing + repellents + burrow exclusion gives the best permanent results
Understanding the Groundhog Problem
Before treating, confirm you actually have a groundhog. Signs include: holes 5–6 inches wide with mounded dirt at the entrance, a large burrowing mammal with a flat head and short legs seen in early morning or late afternoon, gnaw marks on garden vegetables at ground level, and collapsed soil near the foundation or garden beds.
Groundhogs are most active April–September. They hibernate from October to February, so any burrow activity in winter is likely another animal (skunk, rabbit, or opossum) that has moved into a vacant burrow.
1. Woodchuck Fence (Most Reliable Long-Term Solution)
A properly installed exclusion fence is the only method that provides complete, permanent protection. Use 2-inch woven wire mesh or heavy poultry wire:
- Height: At least 3 feet above ground
- Depth: Buried 12 inches underground
- Outward bend: The buried portion should curve outward in an L-shape — groundhogs dig straight down and hit the horizontal barrier
- Top angle: Bend the top 15 inches of the fence outward at 45° — groundhogs are good climbers and this prevents them going over
This fence design also excludes rabbits, deer, and other garden pests — making it the best value investment for any serious vegetable garden.
2. Live Cage Trapping and Relocation
Cage trapping is the most effective removal method when a groundhog is already established. Use a trap at least 10x12x32 inches. Best bait: cantaloupe, fresh lettuce, apple slices, broccoli, or sweet corn — placed at the very back of the trap.
Tips for success: Camouflage the trap with branches and leaves. Place it near the burrow entrance or along their regular travel path. Set it in late afternoon and check at first light. Once caught, relocate at least 5 miles away to wooded habitat. Check local regulations — some states require permits to trap and relocate groundhogs.
3. Castor Oil Repellent
Castor oil is the most scientifically supported natural groundhog repellent. When groundhogs eat grubs or plants coated in castor oil residue, it causes gastrointestinal discomfort, teaching them to avoid the treated area.
DIY recipe: Mix 1 cup castor oil + 1 gallon water and spray across the garden perimeter and near burrow entrances. Reapply every 2 weeks and after heavy rain. Commercial products like Mole-Max or Repellex also contain castor oil and are easy to apply with a spreader.
4. Ammonia Around Burrows
Ammonia mimics predator urine and triggers a flee response in groundhogs. Mix equal parts household ammonia and water. Spray around the burrow entrance and perimeter of the property. For stubborn groundhogs, soak rags in ammonia and stuff them loosely into burrow entrances. The strong odor encourages voluntary eviction. Always wear gloves and avoid applying in windy conditions. Reapply every 2–3 days.
5. Predator Urine
Coyote or red fox urine (available at garden centers) signals active predator territory to groundhogs and causes them to avoid the area. Apply around the yard perimeter, garden beds, and near burrow entrances. Reapply every 7–10 days and after rain. Combine with other repellents for best results — predator urine alone won’t dislodge an established groundhog, but it helps prevent new ones from moving in after you’ve removed the existing one.
6. Epsom Salt
Sprinkle Epsom salt around the perimeter of garden beds and near burrow entrances. Groundhogs dislike the bitter taste and smell. It also benefits garden soil by adding magnesium. Reapply after rain. This is a gentle, low-cost deterrent best used as part of a multi-method approach rather than on its own.
7. Scent Deterrents: Garlic and Hot Pepper
Groundhogs have a strong sense of smell and avoid pungent plants. Puree 3–4 garlic cloves with 2 hot peppers, 1 cup water, and a squirt of dish soap. Strain and spray around garden borders and near burrows. Reapply every 5 days. Planting garlic, onion, lavender, or rosemary around garden perimeters also provides passive long-term deterrence.
8. Scare Devices
Motion-activated devices create a startling environment that discourages groundhogs from settling in:
- Motion-activated sprinklers: Most effective — delivers a harmless water burst when triggered
- Mylar balloons and pinwheels: Flashing movement startles groundhogs; move them every few days
- Reflective tape: String around garden perimeter; creates unpredictable light flashes
- Ultrasonic stakes: Emit vibrations that disturb groundhogs underground; limited range
9. Burrow Exclusion After Eviction
Once you’re sure the groundhog has left, block the burrow permanently. Confirm vacancy by loosely stuffing the entrance with newspaper — if undisturbed for 3 days, it’s empty. Fill the burrow entrance with large rocks, then top with soil. Install a section of fence mesh over the filled hole, anchored with stakes, to prevent re-excavation. Groundhogs are creatures of habit and will try to re-enter known burrow sites.
10. Remove All Attractants
No deterrent works well if your yard is loaded with groundhog food. Keep the garden well-fenced, pick up fallen fruit daily, keep grass trimmed short, remove brush piles and woodpiles near the garden, and eliminate dense undergrowth where groundhogs shelter. A groundhog that finds nothing easy to eat will move on within a few days.
Why Gas Bombs Are Not Recommended
Gas bombs (carbon monoxide cartridges) are marketed for burrowing pest control but are not recommended: they’re inhumane, illegal in many states, can leave gas residue in the soil that harms other wildlife, may not penetrate deep enough to reach the animal, and are unnecessary given the effective humane alternatives above. Always check your local wildlife laws before any groundhog removal.
Frequently Asked Questions
What is the fastest way to get rid of a groundhog?
Live cage trapping gives the fastest results — most groundhogs are caught within 1–3 nights when the trap is properly placed and baited. After relocation, immediately install an exclusion fence or block the burrow to prevent a replacement groundhog from moving in.
What do groundhogs hate the most?
Groundhogs strongly dislike the smell of predator urine (coyote, fox), ammonia, garlic, and hot peppers. They also avoid open spaces with no nearby cover. Combining scent deterrents with habitat modification (removing brush and cover) is highly effective.
Will a groundhog come back after being relocated?
Studies show groundhogs relocated less than 2 miles from their original territory often return. Relocate at least 5 miles away, in wooded habitat away from residential areas. Seal the burrow immediately after relocation to prevent return or a new groundhog moving in.
Are groundhogs dangerous?
Groundhogs rarely pose a direct danger to humans and generally flee rather than confront. However, they can carry rabies and other diseases. Never handle a groundhog with bare hands. If you encounter one that is behaving abnormally (active midday, disoriented, aggressive), contact animal control — this may indicate rabies.
Is a groundhog the same as a woodchuck?
Yes, groundhog and woodchuck are two common names for the exact same animal: Marmota monax. The name “woodchuck” has nothing to do with wood or chucking — it derives from the Algonquin word “wuchak.” Other regional names include whistle-pig and land-beaver. All refer to the same North American marmot species that hibernates October–February and is responsible for the lawn and garden damage associated with burrowing and foraging throughout spring and summer.
How do I get rid of a groundhog under my deck or shed?
Groundhogs denning under structures require a two-step approach: (1) Evict first — place ammonia-soaked rags, predator urine, or a motion-activated sprinkler near the burrow entrance to encourage voluntary departure. Confirm the groundhog has left by loosely plugging the entrance with newspaper and checking after 3 nights. (2) Permanently exclude — install heavy-gauge wire mesh (hardware cloth) around the full perimeter of the deck or shed, buried 12 inches underground in an L-shape. This prevents re-entry by the same animal or a replacement moving into the vacated burrow.
When do groundhogs hibernate and will the problem naturally resolve?
Groundhogs typically enter hibernation October–November and emerge February–March. While the individual animal is inactive during winter, the burrow remains — and another groundhog (or different animal) will move into the vacated burrow within one season. The problem does not resolve on its own. After evicting a groundhog in late summer or autumn, permanently seal the burrow entrance and install exclusion fencing before the animal returns in spring or a replacement moves in.
