The groundhog, also known as the woodchuck, is a large rodent whose burrowing activity causes significant problems for homeowners. These animals construct complex subterranean networks that can extend up to 100 feet in length and reach depths of 3 to 6 feet. This tunneling can undermine the structural integrity of foundations, decks, and concrete slabs, leading to soil erosion and costly repairs. Groundhogs also pose a threat to landscaping and gardens, as they have a voracious appetite for a variety of vegetation.
Confirming Occupancy and Legal Restrictions
Before filling a groundhog hole, confirm that the burrow is unoccupied. A simple method involves loosely plugging the entrance with crumpled newspaper, sticks, or a light layer of soil and checking it daily for three to five days. If the material is pushed out, the burrow is active, and sealing it is not only ineffective—as the animal will simply dig a new exit—but also inhumane.
Check local and state wildlife regulations before taking any action against a nuisance animal. Many jurisdictions classify groundhogs as regulated species, meaning there are strict rules regarding their removal, relocation, and humane dispatch. In some areas, live-trapping and relocating the animal is illegal without a specific permit, as it can spread disease or cause distress. Understanding these local ordinances is a prerequisite to any removal plan.
Humane Methods for Encouraging Groundhog Eviction
The goal of eviction is to make the existing burrow undesirable, encouraging the groundhog to relocate. One of the most effective humane methods is the installation of a one-way exclusion device, often a wire mesh funnel or door. This device is secured over the main burrow entrance, allowing the groundhog to exit freely but preventing it from re-entering the hole. This method should not be used during the spring and early summer (typically May through August) to avoid trapping dependent young inside the burrow.
Sensory deterrents can also encourage the animal to leave the area. Placing non-toxic, strong-smelling substances near the entrance can irritate the groundhog’s sensitive nose. Rags soaked in ammonia or granular repellents containing castor oil or capsaicin can be placed outside the main opening to make the area unpleasant. Removing nearby food sources, such as fallen fruit or clearing dense vegetation that provides cover, will also make the habitat less appealing.
Do not use dangerous or illegal substances to flush out a groundhog. Pouring gasoline, bleach, or other chemical poisons down a hole is hazardous to the environment, pets, and groundwater, and can be legally prohibited. Similarly, flooding a complex burrow system with large amounts of water is ineffective and can cause the tunnel to collapse, further undermining nearby structures.
Safely Sealing and Filling the Burrow
Once the burrow is confirmed inactive for several consecutive days, physically stabilize the ground by filling the tunnel system. It is important to use materials that will not easily resettle or be re-excavated by a new animal. Loose topsoil alone is not sufficient, as it will compact over time, leaving a depression that can collect water.
The most stable materials for filling a groundhog burrow are coarse sand, gravel, or a mixture of soil and crushed stone aggregate. These materials should be compacted in layers rather than poured in all at once to ensure a dense fill that prevents future sinking or collapse. For large voids, especially those under concrete slabs or foundations, a professional may use a specialized flowable fill or a high-sand content concrete slurry mix that flows into all subterranean pockets.
After filling the primary entrance, cover the area with a piece of heavy-gauge welded wire mesh, approximately three feet square. This mesh should be centered over the filled hole and buried just beneath the topsoil. This physical barrier prevents a new or returning groundhog from easily digging into the same compromised spot, ensuring the structural repair remains intact.
Long-Term Strategies for Prevention
The most reliable long-term solution for preventing groundhogs from returning is installing proper exclusion fencing. Since groundhogs are adept diggers, a simple vertical fence is easily bypassed. The barrier must be constructed using heavy-gauge wire mesh, ideally with openings no larger than two inches.
The fence should stand at least 3 feet high and its base must be buried into the ground a minimum of 10 to 12 inches deep. The buried portion requires an L-shaped flange, or apron, bent outward at a 90-degree angle away from the protected area. This outward bend, which should extend 12 to 18 inches, acts as an underground deterrent plate. When a groundhog attempts to dig under the fence, its natural tunneling angle is blocked by the horizontal mesh, causing it to abandon the effort.
Beyond fencing, property maintenance is important to reduce the appeal of the area. Structures like sheds and decks should be checked for vulnerable ground-level entry points that offer immediate shelter. Keeping woodpiles off the ground and regularly mowing dense grass reduces cover, making the area less attractive for a groundhog.