Chipmunks are small, active members of the squirrel family that become persistent garden nuisances due to their omnivorous diet and burrowing habits. They are primarily attracted to gardens for seeds, flower bulbs, and fruits, often causing damage by excavating tunnels or harvesting newly planted items. Burrow entrances, typically two inches in diameter and lacking a dirt mound, can destabilize structures over time. Successfully managing a chipmunk population in the garden requires a multi-faceted approach focusing on humane, natural deterrence.
Eliminating Food Sources and Environmental Attractants
The first approach to natural chipmunk control involves removing the primary reasons they visit your garden, which are easy access to high-calorie food and water. Chipmunks are highly opportunistic feeders, and common backyard items like birdseed, pet food, and fallen fruits are strong attractants. Sunflower seeds, for instance, are especially favored due to their high fat content, which helps chipmunks meet their energy needs.
When using bird feeders, choose seed types less favored by chipmunks, such as thistle or safflower, and always clean up any seed spillage beneath the feeder daily. Securing outdoor pet food is also important; store dry food in sealed, rigid containers indoors rather than in accessible bags in a shed or garage. Additionally, promptly picking up fallen nuts, berries, and ripe fruit from the ground reduces their foraging opportunities.
Chipmunks require water, especially during the breeding season, and will seek out any available source. Addressing leaky hoses, dripping spigots, or shallow containers of standing water can remove an environmental attractant. Clearing dense groundcover, woodpiles, or rock walls immediately adjacent to the garden also removes protective cover, making the area feel less safe for them to forage and build burrows.
Structural Exclusion Methods for Garden Beds
Physical barriers provide the most reliable, long-term solution for protecting vulnerable garden beds and newly planted materials. The material of choice for exclusion is sturdy galvanized hardware cloth. A mesh size of one-quarter inch is recommended because it is small enough to prevent the chipmunk from squeezing through or chewing on the barrier.
For raised beds or perimeter fencing, the hardware cloth must be installed not just vertically, but also horizontally beneath the soil to prevent burrowing. This is accomplished by creating an “L-shaped” barrier, where the mesh extends at least six inches deep into the ground. At the bottom of this vertical section, the mesh is bent outward at a 90-degree angle to extend another six to eight inches horizontally beneath the surface. This horizontal skirt prevents the chipmunk from digging directly underneath the fence line.
When planting valuable bulbs like tulips, which chipmunks frequently excavate, individual exclusion cages can be constructed. Wrap the bulbs in a small enclosure made from the same quarter-inch hardware cloth, leaving enough room for the shoot to grow through the top. For temporary protection of ripening vegetables and berries, fine mesh netting or row covers draped over hoops can be used, ensuring the edges are secured firmly to the ground to block access from the sides.
Utilizing Natural Scent and Taste Repellents
Sensory deterrents offer a non-lethal way to make a garden area unappealing by stimulating the chipmunk’s sense of smell or taste. Capsaicin, the compound responsible for the heat in chili peppers, is an effective taste repellent that causes a mild, unpleasant sensation when ingested.
A simple capsaicin-based spray can be created using water and cayenne pepper, or you can purchase commercial sprays that utilize this ingredient. This solution is best applied to the perimeter of the garden or directly onto non-edible plants and bulbs, as spraying food crops is not advisable. Another powerful scent deterrent is peppermint oil, which has an aroma that is overwhelming to small rodents.
Peppermint oil can be diluted with water and sprayed around burrow entrances and along garden borders. For an additional layer of deterrence, commercial repellents that mimic predator scents, such as fox or coyote urine, can be strategically placed near high-traffic areas. The effectiveness of all scent and taste repellents diminishes over time and with exposure to moisture. Therefore, frequent reapplication, especially after rain or watering, is necessary to maintain a strong deterrent effect.