Voles are small, mouse-like rodents that cause significant damage to gardens and landscapes by feeding underground on plant roots, bulbs, and tubers. These herbivores also gnaw on the bark of young trees and shrubs, often girdling them just above the soil line, which can lead to the plant’s death. Unlike moles, which are carnivorous and tunnel for insects, voles create surface runways and target the vegetation itself. Many gardeners prefer to avoid harsh chemical controls, leading to interest in natural, plant-based solutions. The strategic use of certain plants, chosen for their taste or strong aroma, offers an ecologically sound way to discourage voles.
How Botanical Deterrents Work
Plants that successfully deter voles operate through two main biological strategies: unpalatability and olfactory disruption. The first method involves the plant producing compounds that are inherently toxic or extremely bitter to the rodent. These chemical defenses, often complex alkaloids, make the plant an undesirable food source, causing the voles to seek nourishment elsewhere. A vole may take an initial exploratory bite, but the immediate noxious taste signals that the plant is not safe to consume.
The second primary mechanism is the release of strong, pungent essential oils into the soil and air. Voles rely heavily on their sense of smell to locate food sources and navigate their underground tunnels. Intense aromas from certain plants can confuse the rodents, effectively masking the scent of nearby preferred bulbs and roots. The overwhelming odor acts as a repellent, forcing them to move away.
Highly Toxic or Unpalatable Bulb Plants
Many of the most effective plant deterrents contain bitter or poisonous substances that voles instinctively avoid. Daffodils (Narcissus genus) are widely known to be unbothered by rodents because their bulbs and foliage contain the alkaloid lycorine. This compound is intensely bitter and toxic, making the entire plant a poor choice for a hungry vole. Planting daffodils is a reliable way to protect a garden area.
Another potent deterrent is the Crown Imperial (Fritillaria imperialis), sometimes called “skunk lily” due to its distinct, musky odor. The bulbs contain high concentrations of alkaloids that are unpalatable to voles. Similarly, the Lenten Rose (Helleborus species) contains toxic compounds that make it highly unappealing. Other bulb varieties, such as Snowdrops (Galanthus) and Siberian Squill (Scilla siberica), also contain compounds that rodents find extremely bitter. Gardeners should note that highly toxic plants, including Castor Bean (Ricinus communis), should be planted with caution, especially in areas frequented by children or pets.
Aromatic Herbs and Flowers that Repel
Plants that actively disrupt a vole’s sense of smell provide an important layer of defense against tunneling rodents. The entire Allium family, which includes ornamental onions, garlic, and chives, is highly effective. These plants release sulfurous compounds that create a strong, pungent aroma in the soil that voles find offensive. Planting these throughout a bed can help mask the scent of more desirable roots and bulbs, confusing the voles as they search for food.
Other herbs and flowering plants also use powerful essential oils to deter these pests. Lavender is known for its strong, fragrant blooms and foliage, which contain oils that voles dislike. Rosemary is another woody perennial that releases fragrant evergreen oils, effectively repelling voles while also benefiting pollinators. The strong, minty scent of plants like Peppermint (Mentha x piperita) and certain varieties of Sage (Salvia) also contribute to an environment that voles choose to avoid.
Strategic Planting for Maximum Protection
Simply placing a few deterrent plants in the garden may not be sufficient; their placement must be intentional to maximize protection. One effective technique is “barrier planting,” which involves establishing a dense, continuous perimeter of deterrent plants around a vulnerable area. Planting a thick border of daffodils or Crown Imperial around a bed of prized tulips creates a toxic, unappealing wall that voles are reluctant to breach. This strategy leverages the toxicity of the plants to discourage entry.
Another successful method is “interplanting,” which involves mixing the aromatic deterrent plants directly among the vulnerable crops. By scattering garlic, chives, or ornamental onions throughout a vegetable patch, the strong odors are distributed across the entire area, confusing the voles’ sense of smell. This diffusion of scent makes it difficult for the rodents to home in on their preferred food sources. Planting deterrents near known tunnel entrances or runways can actively push the vole population away. The success of these methods depends on the density and proximity of the deterrent plants to the desired food source.