Pocket gophers are subterranean rodents that damage gardens and lawns by creating extensive tunnel systems and feeding on plant roots. These pests cause frustration for gardeners, leading to questions about using pungent plants like garlic as a defense. The belief is that garlic, with its strong odor, may either be avoided as a food source or serve as a natural repellent. Examining the gopher’s specific diet provides clarity on how this pest interacts with the bulb.
Gopher Dietary Preferences
Gophers are strict herbivores whose diet is centered on the underground parts of plants, including roots, tubers, and bulbs. They are opportunistic feeders, capable of consuming nearly half their body weight in vegetation daily to sustain their active burrowing lifestyle. They will often pull entire plants, like grasses and forbs, into their burrows from below the surface. While they favor nutrient-rich crops such as carrots, alfalfa, and sweet potatoes, their diet is broad and changes based on the availability of food sources in their immediate environment.
Gopher Consumption of Garlic
Garlic bulbs are generally avoided by gophers as a preferred food source. The strong, pungent nature of the garlic bulb is attributed to sulfur compounds, which make it unpalatable compared to the sweeter, starchier roots they seek. These sulfur compounds are released when the bulb is damaged, creating a taste and odor barrier that deters most gophers.
While a gopher may accidentally chew through a garlic bulb while tunneling, they rarely target the clove itself for sustenance. Reports of gophers eating garlic are usually associated with periods of extreme food scarcity, suggesting it is a last resort rather than a favored meal.
Using Garlic as a Gopher Deterrent
The strong odor that makes garlic unappealing to eat is the basis for its use as a common, non-lethal deterrent. Gardeners frequently place garlic cloves or crushed garlic directly into active gopher tunnels or mounds. The goal is to introduce the intense sulfurous scent into the confined burrow system, encouraging the pest to relocate.
Another application involves creating a garlic-based slurry or spray mixed with water and soap. This liquid is poured down the tunnel openings to saturate the surrounding soil. While the strong smell provides a temporary, localized scent barrier, the effectiveness is often short-lived. The volatile compounds quickly dissipate, and gophers can simply tunnel around the treated area. For a persistent infestation, garlic-based deterrents are typically a low-efficacy solution.
Proven Non-Garlic Control Methods
Since scent-based deterrents often fail to provide a permanent solution, the most reliable control methods focus on physical exclusion and direct removal. Exclusion involves placing a physical barrier between the gopher and the plant roots it seeks to consume. This is accomplished by installing gopher baskets made of galvanized hardware cloth or wire mesh with a maximum opening of three-quarters of an inch around the roots of individual plants.
For larger areas, such as lawns or raised beds, a subsurface barrier of the same hardware cloth should be installed at least 12 to 18 inches deep.
Trapping
The most effective method for controlling a small-scale infestation remains trapping, which targets the pest directly. Traps, such as the Macabee or box trap, are set in pairs facing opposite directions within the main tunnel run and must be checked frequently for success.
Certain plants are also known to discourage gopher activity due to toxicity or taste, though they do not guarantee protection. Plants like the castor bean and gopher purge are frequently cited as deterrents, but caution is necessary as these are toxic to humans and pets. Ultimately, a combination of physical barriers and systematic trapping provides the highest level of protection against gopher damage.