Known as field mice in the US, voles are hairy rodents. These members of the Arvicolinae subfamily, which also includes muskrats and lemmings, are often morphologically mistaken for shrews and wild hamsters. Unsurprisingly, they are also frequently confused with moles due to their near-identical common names and their shared tendency to burrow in substrates. Unlike moles, however, voles are equipped with fully functional eyes.
An even starker difference between these two animals lies in their food preferences. While subterranean moles tend to be carnivorous, voles prefer to stick to their vegetarian diet. They use their nimble and skinny claws to grasp delicate stems and juicy stalks of grass. They may also feed on the root systems of young plants, preventing them from becoming well-established and increasing their spread.
Voles don’t live in the ground, but they do create tunnels to swiftly move from one patch of plants to another. Some clear signs of their presence include holes (seldom wider than a golf ball) in the ground and cracks in the soil, usually around tuberous or bulb-producing crops, tender herbs, and grasses. The plants below should help discourage them from wreaking widespread damage in ornamental gardens and around commercially important crops.
1) Daffodils (Narcissus spp.)
Beloved by many horticulturists in temperate zones, daffodils are widely cultivated for their reliable springtime blooms. Usually solitary, these are set apart by their cone-shaped coronas, rings of solid-colored petals, and a fairly lengthy floral tube. Each bloom is borne on a hollow floral stem with a few narrow leaves. The entire plant is anchored by a storage bulb and short roots, which remain underground throughout the growth period.
Daffodil bulbs are quite effective at repelling a host of pests, especially those with a knack for digging out roots and creating tunnels in the ground. Along with the leaves, they contain a complex mixture of unique alkaloids, many of which have toxic properties. Though some major garden pests (e.g. nematodes) are not necessarily repelled by these chemicals, their ingestion can lead to troublesome symptoms in herbivorous mammals.
Physical contact with phytochemicals in daffodil bulbs and leaves may also cause painful allergies. Lycorine, one of this genus’ major alkaloids, can have lethal effects when it is inadvertently consumed in large quantities. Thus, situating daffodil bulbs around more susceptible crops should have voles second-guessing the appeal of your garden.
2) Common onion (Allium cepa)
Another bulbous plant with unrivaled commercial value, the humble onion can bring many ecological services to the home garden. This pungent vegetable, often treated as an annual crop despite its capacity to persist in the wild as a perennial, has been intentionally cultivated for millennia. Its modern varieties have bluish green leaves which arise in a fan-shaped orientation. These are borne on a yellowish or reddish bulb with layers of juicy tissues.
Even immature onions are packed with strongly scented chemicals that can scare off the most determined herbivores. Voles, which dislike their scent and taste, are unlikely to create tunnels or exit holes that are too close to a plot or border of onions. Known for being dangerously toxic to larger mammals like dogs and cats, onions can cause a host of allergic reactions, including severe nasal and olfactory irritations.
If you are interested in harnessing the deterrent effects of onions but struggle to find the right spot for them in your garden, consider investing in onion powder. This can be sprinkled around zones with suspected vole activity. A dash of powder in a vole hole should render it inhospitable to resident tunnellers, forcing them to search for food elsewhere.
3) Crown imperial (Fritillaria imperialis)
A member of the diverse Liliaceae family, the crown imperial unfailingly draws attention. This beautiful species has erect features which measure up to 3 feet (91 cm) tall at maturity. Its straight stems bear striking, glossy, and lance-shaped leaves. These complement the graceful appearance of its spring inflorescences.
As suggested by its common name, this plant’s bright-orange, downward-facing blooms are arranged to form a vibrant crown. Each inflorescence is topped with a tuft of short, lively leaves, which may look peculiarly misplaced to those who gaze upon them for the first time. As though its morphological features weren’t interesting enough, its flowers have evolved to emit a distinctly foxy or musky aroma. Voles, moles, mice, and other small mammals are deterred by the strong scent.
Like onions and daffodils, the crown imperial also bears bulbs. In their raw form, they are toxic due to the presence of alkaloids. In the wild, these phytochemicals likely protect the plant from being wholly devoured by herbivores.
4) Grape hyacinth (Muscari armeniacum)
The most popularly cultivated member of its genus, the grape hyacinth is a lovely herb with fantastic ornamental qualities. This spring-blooming bulb produces floral stalks with seemingly heavy inflorescences. These consist of tightly packed, bell-shaped blooms that resemble – of course – juicy grapes! The downward-facing blooms attract many spritely pollinators and may eventually develop into bright green seed pods.
Perfect for creating colorful patches in rocky borders or for mass plantings that create the illusion of a flowing, blue-violet stream, grape hyacinth thrives best in partial shade. If voles and other small rodents are likely to terrorize the shaded zones of your yard, consider planting a few carefully situated plots of this species. Voles are unlikely to eat their bulbs and leaves, making them the perfect candidates for a low-maintenance garden.
As a bonus, grape hyacinth is also fairly resistant to grazing from larger mammals like deer and rabbits. Its impressively hardy yet delicate stands can help complement nearby flowering perennials and protect them from potential pests. For this reason, it is a recipient of the RHS Award of Garden Merit.
5) Lenten rose (Helleborus orientalis)
If your vole-repellent garden needs some winter interest, consider growing a few specimens of the stunning Lenten rose. This flowering perennial is a charming, low-maintenance member of the Ranunculaceae or buttercup family. It is an exceptional plant due to its tendency to bloom in late winter, when many other flowering plants remain dormant.
As the Lenten rose comes in a wide range of hybrids, its cup-shaped blooms may be pink, yellow-green, cream, plum, or yellow. These are typically speckled and contain modified petals in which nectar is stored. While many beneficial pollinators are attracted to this species, they are known for deterring a handful of common garden pests, including voles.
Virtually all parts of H. orientalis contain toxic phytochemicals. Its sap can irritate the digestive tract of any herbivores that attempt to ingest its leaves, stems, flowers, or roots. In fact, the name of its genus is rooted in Greek words (helein + bora, which means “injuries + food”) that allude to this plant’s toxic properties. Use its stands to create a vole-repellent border in the shadier parts of your garden.
6) Monkshood (Aconitum spp.)
Monkshood refers to any one of around 250 species listed under the Aconitum genus. Also called wolfsbane, blue rocket, or devil’s helmet, these flowering plants are known for being remarkably poisonous. Despite their toxic nature, however, they are favored by many horticulturists due to their ornamental qualities. Some of these species produce wonderful blooms and highly-textured leaves.
The toxic phytochemicals of most monkshood species are usually concentrated in their roots and in their underground tubers. Aconitine, a potent alkaloid, functions as a neurotoxin in animals that may inadvertently ingest the leaves and roots of the plant. Highly toxic, it can lead to fatal consequences even if it is consumed in minute concentrations. Herbivores that mistakenly eat these plants initially experience symptoms like vomiting or diarrhea. Physical contact with their sap can cause headaches and palpitations!
While this is definitely a force for voles to reckon with in a productive garden, it may not be the most ideal plant if you have pets or children. If you intend to grow a few stands of monkshood to keep rodents away, make sure to place them in spots where they are unlikely to attract curious passersby.
7) Garlic (Allium sativum)
To deter voles around plots of edible crops, try planting rows of garlic bulbs. This wonderful member of the Amaryllidaceae family is arguably one of the most commonly used biopesticides. It contains a wealth of strongly scented phytochemicals, many of which can mask the scent of susceptible plants, act as natural antimicrobials, and generate unappealing sensations in the digestive tracts of grazers.
With a history in cultivation that dates back to several thousand years ago, garlic is now commercially important all across the globe. This means that its pest-repellent properties can be utilized by just about anyone with access to a supermarket. If you’re lucky enough to have a farm or garden in a region with mild climate conditions, it would be a great idea to cultivate your own plot of garlic.
While dense rows of intact garlic bulbs may provide a measure of protection against voles, it would be best to harvest them and use their oils in a more targeted manner. Crush the garlic cloves into a fine pulp and transfer the strongly scented fluid into a water-based mixture. Spray this solution into suspected vole holes and around vulnerable plants.
8) Common snowdrop (Galanthus nivalis)
The common snowdrop is a lovely flowering perennial for gardens in temperate zones. Its beauty is accentuated in late winter or early spring, when its tiny white buds open into fragrant blooms that nod in the slightest breeze. Starkly white, these can be numerous enough to generate swathes of petals that cover the garden as a carpet of snow would. Sweeping clusters can significantly brighten up dim spaces.
This groundcover herb is amazingly resistant to many mammalian herbivores and troublesome critters. It can grow and spread quickly in well-draining substrates with either full or partial sun exposure. One of the adaptations behind its success as a garden plant is the formulation of phytochemicals in its sap. It contains a type of lectin (scientifically referred to as GNA or Galanthus nivalis agglutinin) that is toxic to grazers.
Though the common snowdrop deters leaf-eating insects and mammals, it attracts a wealth of beneficial insects and pollinators. Its stands may be abuzz with activity in early spring, making for an unforgettable sight as ambient temperatures just begin to warm. Voles won’t dare attempt to destroy such a delightful scene!
9) Castor bean (Ricinus communis)
A notable member of the Euphorbiaceae or spurge family, R. communis is known as the source of pure castor oil. This multi-use vegetable oil is obtained from castor beans. Contrary to the plant’s common name, these are not actually “beans” in the technical sense. These are highly toxic, oval-shaped seeds that are contained in distinctly spiky capsules.
The sap contained by the leaves, seeds, and flowers, coupled with this species’ allergy-inducing pollen and toxic seeds, is able to deter all sorts of grazers. Contact with or ingestion of the pollen or oils can lead to rashes, nausea, diarrhea, seizures, a burning sensation in the digestive tract, and hypotension. Store-bought castor oil can be introduced into the upper layers of soil to protect the crowns of developing plants.
You can reasonably expect voles and many other small mammals to keep well away from natural borders consisting of castor bean shrubs. Though these are impressive as pest-repellent plants, they are also commonly grown for ornamental purposes. Reinforce your garden’s hardiness by growing this species in key areas, such as along the perimeter and close to plots of susceptible herbs.
10) Peppermint (Mentha x piperita)
Voles may rely on their acute sense of smell to search for the most delectable and juicy shoots and roots. This is why strongly scented herbs are perceived as useful tools for masking the presence of valuable crops. Peppermint is, by far, one of the handiest hybrids of the Lamiaceae or mint family. It’s perfect for creating a scent cloud that deters voles and other rodents. Its overpowering and heady aroma signals the presence of bitter alkaloids, diterpenes, and other toxic compounds.
This natural hybrid between watermint (M. aquatica) and spearmint (M. spicata) is now one of the most commonly cultivated herbs. Set apart by its highly textured and fragrant leaves, it is known for being able to spread at a remarkably fast pace, especially in frequently moistened substrates. Its well-established stands are able to send out runners. As it is unable to produce seeds, it relies on this vegetative means of self-propagation to create robust colonies.
If you’re hesitant to grow this hybrid as it may compete with less aggressive plants, consider investing in its pure extracts. This can be mixed into a water-based solution – perhaps one with garlic or cayenne pepper – to create a broad-spectrum, homemade repellent against voles, moles, and more!
