Groundhogs, also known as woodchucks (Marmota monax), are common North American rodents known for their burrowing habits and large appetites, making them significant garden pests. Gardeners often worry about which specific plants groundhogs will target. This article addresses the threat groundhogs pose to the popular ornamental plant, the geranium, and provides context on their broader diet and effective deterrence strategies.
Geraniums on the Groundhog Menu
Groundhogs generally consider geraniums, specifically the common garden species Pelargonium, an unappetizing choice. Many varieties possess a pungent, often citrusy or spicy scent that groundhogs find highly offensive. This strong odor, combined with the slightly bitter taste and low-level toxicity, acts as a natural deterrent to most herbivores.
Scented geraniums are frequently included on lists of groundhog-resistant plants for garden planning. The animal’s foraging behavior is strongly guided by scent, and they typically pass over plants that emit powerful aromatic compounds. While geraniums are not a preferred food source, no plant is entirely immune to being sampled by a desperate or inexperienced young groundhog.
A groundhog may nibble on a geranium when preferred food sources are depleted or unavailable, such as during a drought. However, the initial taste usually confirms its unsuitability, and the animal will move on quickly. Geraniums are likely safe, but their presence will not deter a hungry groundhog from targeting tastier plants nearby.
A Groundhog’s Typical Vegetarian Diet
Groundhogs are nearly exclusively herbivorous, relying on a diverse diet of greens, forbs, and garden vegetables to sustain their large body mass. They are opportunistic grazers, consuming up to 1.5 pounds of vegetation daily during the summer months while preparing for hibernation. Their preference is for tender, succulent leaves and plants that are easy to digest.
Favorite wild foods include alfalfa, clover, dandelions, and various grasses, which provide necessary moisture and nutrients. In a garden space, groundhogs frequently target common vegetables like peas, beans, lettuce, and carrots. They also readily eat fruits such as apples, cherries, and various berries.
The animal’s diet is highly seasonal, often including tree bark and twigs in the fall when other greens become scarce. Groundhogs have sharp, continually growing incisors, allowing them to clip plants cleanly at the base, which is a common sign of their presence. They seek out the path of least resistance for calories, avoiding strong-smelling or toxic plants like geraniums when better options are available.
Effective Methods for Deterring Groundhogs
The most reliable method for protecting a garden from groundhogs is physical exclusion, preventing them from accessing the area entirely. A fence must be constructed using heavy-gauge wire mesh with openings no larger than two inches. Since groundhogs are proficient burrowers, the fence must extend underground to be effective.
To implement physical exclusion, dig a trench approximately 12 inches deep around the garden perimeter. The bottom 6 to 12 inches of the wire mesh should be buried in this trench. The lowest portion must be bent outward into an L-shape facing away from the garden, creating an underground apron that prevents the groundhog from digging beneath the barrier.
Strong-smelling repellents can also be used to make the area less inviting to the groundhog’s sensitive nose. Groundhogs dislike pungent odors like garlic, red pepper, and castor oil. These repellents can be applied as a granular barrier around burrows or sprayed directly onto targeted plants.
Commercial products containing predator urine, such as coyote or fox scent, are also available. These can be sprayed near burrow entrances to mimic the presence of a natural enemy. Although these deterrents require frequent reapplication, especially after rain, they can convince a groundhog to forage elsewhere. Combining physical exclusion with scent-based repellents offers the most comprehensive protection.