It’s one of those lovely, sunny days that invites you out to the garden. You make your way around planting beds just coming to life after a long winter but wait, where are those tulips you planted last fall? You notice, to your dismay, little trails or mounds in the soil, and perhaps little holes here and there. If you haven’t met them before, you’re about to become acquainted with a pair of furry little critters that just love your garden: moles and voles.

Moles

Voles are not the only pests responsible for runways in the garden and they’re often confused with those other fellows you’d like to get rid of: moles. Moles make two types of runways in your yard. One is just beneath the surface, called feeding tunnels. These are the raised ridges that usually alert you to their presence. Others are deep below the surface and act to connect the feeding tunnels. The soil excavated from these tunnels forms the mounds distributed where moles have been active. Voles, however, leave no mounds.

While there are some similarities between moles and voles, they are fundamentally very different creatures. Moles could be considered beneficial. They characteristically have a large snout. They have the ability to tunnel with their

Mole

modified paws. Their tunnels beneath the soil surface can act to aerate the soil. Moles also eat insects, grubs, and earthworms, rather than plants. Moles don’t intentionally harm plants, although their tunnels may dislodge roots and cause those plants to dry out more quickly.

Pine Voles

Voles are smaller than moles, about the size of a mouse. They sometimes dig tunnels, but they are also opportunists and have been known to travel about in those tunnels previously dug by moles.

In NC we have two types of voles: pine voles and meadow voles. The pine vole, Microtus pinetorum, is becoming a bigger problem in the home landscape as increased development reduces their natural habitat and they become more adapted to our backyards. These are the prime suspects for the missing tulip bulbs.

Pine voles are reddish brown and small, 2-4 inches long, with a short tail, blunt face, and tiny eyes and ears. They feed mainly on roots and tubers of plants that do not have poisonous tissues. They spend much of their time under leaf litter or in their underground burrows. They don’t hibernate and, even though we rarely see them, they are active day and night. Their lifespan averages anywhere from two to 16 months. A pair of voles can have up to six litters a year, with two to four young per litter. Pine voles are monogamous and family units tend to maintain territories as small as 1000 square feet and remain there for their entire short lives. So, you can see, when they arrive and set up housekeeping in your garden, you’d be wise to step up to (or on to) the challenge.

Taking Action

In the ongoing wars to protect the gardener’s tender and precious plantings from the ravages of voles, a myriad of attack weapons have been developed, humane and otherwise. Just check out the shelves of your favorite lawn and garden store or the online catalogs: these include repellants (short-term results only), devices (don’t work), rodenticides (designed to kill mammals…think pets), baits and traps.

The extent of plant loss or damage in relationship to vole populations should be considered when choosing which way to approach the problem. Safe and non-toxic methods like exclusion, the installation of underground physical barriers, have proven to be effective because voles aren’t fond of getting cut or injured. These methods generally don’t involve chemicals and are safe to use in the presence of humans, pets, and wildlife. However, reduction in natural vole habitat also reduces habitat for their natural predators (owls, hawks, snakes, etc.). These predators depend on rodents as a food source and possess sensory abilities for locating their meals.

We know and are grateful for the fact that voles are not fond of daffodils. But, when you try again (and you will, you know) to develop that lovely bed of tulips or other savory plantings, you might want to try a safe and humane approach. Incorporating coarse particles like expanded slate into the beds has proven to be an effective barrier to pine voles. Some have found it helpful to mix sharp-edged pea gravel throughout the soil as they prepare a new planting bed. Products such as Perma-Till and VoleBloc can be useful deterrents when used in this way. While not cheap, these methods do not pose ongoing risks to the environment or to the neighbor’s favorite pet.

Updated from the April 9, 2014 article by Celeste M. Bissell, who was the president of the Extension Master Gardener Volunteers at North Carolina Cooperative Extension in Lee County.

Resources:

• Extension Gardener
• NC State TurfFiles