Chipmunks are small, striped rodents frequently observed darting across lawns and scurrying into rock walls, making them common visitors to many backyards. These animals are omnivores, consuming a wide array of food sources, including a substantial amount of plant matter. Chipmunks do eat plants, often leading to frustration for gardeners and homeowners concerned about damage to landscaping. Understanding their foraging behaviors and specific food preferences is the first step in protecting vulnerable areas of your property.
Understanding the Chipmunk Diet
Chipmunks have a broad diet that includes both vegetation and small animal matter, but they primarily focus on harvesting and caching seeds and nuts. Their diet consists heavily of acorns, hickory nuts, sunflower seeds, and various tree seeds. They transport these items in their large cheek pouches to store in underground burrows for winter sustenance. This caching behavior is a major source of garden disruption, as they actively seek out and excavate any newly planted seeds or bulbs they encounter.
Chipmunks consume the underground storage organs of plants, specifically targeting flower bulbs such as tulips and lilies. Beyond seeds and bulbs, they eat soft fruits like strawberries and low-hanging tomatoes, along with tender plant shoots and greens. Their omnivorous nature also extends to consuming fungi, insects, earthworms, and even small vertebrates like bird eggs, demonstrating an opportunistic approach to foraging.
How to Identify Chipmunk Damage
Identifying chipmunk activity relies on recognizing the distinct signs they leave behind, which helps differentiate their damage from that of other garden pests. The most reliable indicator of chipmunk presence is the discovery of small, clean-cut, round holes in the soil, typically about 1.5 inches in diameter. These holes lack a noticeable mound of excavated dirt around the entrance. They are entrances to extensive burrow systems, which can tunnel up to 30 feet long and three feet deep, often located near foundations, retaining walls, or dense plantings.
When feeding, chipmunks completely remove and consume freshly planted seeds or bulbs, leaving an empty cavity in the soil. Unlike voles, which leave shallow surface runways, or moles, which create raised soil ridges, chipmunks’ digging focuses on accessing food caches or creating new entrances. Soft fruit damage usually appears on low-hanging items, marked by small, ragged chew marks close to the ground.
Strategies for Deterrence
Effective chipmunk deterrence involves a multi-pronged approach combining habitat modification with physical and sensory barriers. Start by removing easy food sources, including cleaning up fallen nuts, fruit, and birdseed from the ground, as spilled seed is a major attractant. Clearing away brush piles, wood stacks, and dense debris also reduces sheltered hiding spots and potential entry points they use to access burrows.
Physical exclusion is the most reliable method for protecting specific plants and bulbs. Installing a barrier of quarter-inch hardware cloth or chicken wire over garden beds and bulb plantings prevents digging access. For long-term protection, the mesh should be buried a few inches into the soil and extended above ground level. A “moat” of gravel or crushed stone around foundations or garden edges discourages burrowing, as chipmunks find the material difficult to tunnel through.
For taste and scent-based repulsion, several non-toxic options can be applied directly to vulnerable plants. Sprays containing capsaicin, the compound that gives chili peppers their heat, are effective because chipmunks dislike the taste. Other strong-smelling deterrents, such as peppermint oil, garlic, or used coffee grounds, can be sprinkled or sprayed around plants to make the area less appealing for foraging. Planting naturally deterrent bulbs like daffodils or alliums, which contain compounds chipmunks find distasteful, can create a protective barrier in flower beds.