Jennifer Schultz Nelson
Extension Educator, Horticulture
I'm usually a nature lover, but at the moment Mother Nature is trying my patience. With winter approaching, it seems that voles have decided my flower beds would be perfect places to set up housekeeping for the winter. Normally I'm very tolerant of sharing my landscape with wildlife, but when they start trashing the place I consider that a declaration of war.
It all started last fall when I noticed what I thought was a tiny brown field mouse sitting near the birdfeeder next to my patio. When he saw me he quickly scurried to a small hole he'd made near one of my mums.
I briefly considered putting out a trap near the hole, but I just couldn't bring myself to do it. What was he hurting? He just wanted a few bird seeds and a warm place to spend the winter. Little did I know he would not be alone for long.
Word got out that there were five star accommodations at the Nelson's, complete with fresh mulch, bird feeders, and a fine selection of the latest annuals and perennials to feast upon. I noticed a few more holes over the winter and thought it best to move the bird feeders a good distance from the house. But it was too late.
It was just like the movie "Field of Dreams" where the main character is told "If you build it, they will come". But unfortunately in our case we weren't talking about baseball greats. We had unknowingly invited some furry houseguests to our yard whose only intention was to strip and pillage the gardens my husband I have been working very hard to create.
Over this past summer I did notice the occasional hole, but told myself it wasn't a problem. I live near woods and fields, and having a few furry friends was to be expected. It's not like I had found any damage they had caused. They were being polite houseguests.
I came to my senses last week when I saw one of these little creatures in my garage. They had crossed the line, despite my prevention tactics of placing poison baits strategically around the garage perimeter.
I took a closer look at my flower beds, and noted there were a lot more holes than had been there in the summer, plus clear paths between the holes. Concerned, I went out and bought some traps, hoping to avoid a hostile takeover of my garage and flower beds.
The first night I caught two of what I thought were field mice right outside the garage door. Further research revealed that they were probably voles. Voles are rodents similar to mice, but have small, sometimes barely visible ears and eyes, grey or buff abdomens and their tails are usually shorter than their body. A true field mouse, or deer mouse, has large ears and eyes, white feet and abdomen, and a tail about as long as its body. The paths, or runs in my flower beds are another indicator that I was dealing with voles.
I've come to realize that I inadvertently set up a vole paradise in my flower beds. The mulch that is so helpful at reducing weeds among my flowers is also the perfect media in which to construct a vole metropolis. The bird feeders that my cat loves to watch from the window were also beckoning voles from far and wide. Seed heads and vegetation from my annuals and perennials are also a food source. Perennial roots and crowns are a delicacy, as I found out when I tugged on one only to find no roots attached. These same plants also provide valuable cover and protection from predators.
Voles mature in around forty days, sometimes sooner, and can have five to ten litters of up to six young each in a year. So it's no wonder that the lone occupant I saw last year has ballooned to problem levels in a short time.
My options are basically: habitat management, exclusion, repulsion, or removal. Removing mulch is one way to discourage the voles by changing the habitat, but it's not very good for my plants. Keeping mulch away from the base of plants helps keep voles from damaging them, since they prefer the cover and protection of mulch while feeding. If damage to seedlings and young trees continues to be a problem, surrounding these plants with wire mesh buried six inches deep can help exclude voles.
Cleaning old vegetation and weeds from garden areas reduces cover that protects voles from predators. Another option is to periodically till the mulched areas to discourage and disrupt the population. My usual gardening habits do stir up the mulch and that is probably why I didn't notice much vole activity during the summer.
There are some products available with limited long term effectiveness that repel voles. Some of these products contain the ingredient Thiram, a sulfur containing compound with a bad odor. Other products contain capsaicin, the "hot" in hot chili peppers. Some of the available repellents have restrictions on their use in food crops, so read the label carefully before use.
Removal includes trapping or poison baits. Trapping using mouse traps baited with peanut butter or apple placed at right angles to their runs or burrow openings is recommended. Voles tend to stick to their runs, and this placement forces them to run over the trigger for the trap. I've had luck with traps, but a large infestation can be very difficult to control this way. Live traps do little to help the problem, they just spread it around.
The use of poison baits has a host of risks. For one, some of the effective poisons labeled for voles cannot be applied by homeowners. There is a clear risk that non-target animals like dogs, cats, birds, or young children will consume the bait and be affected. There is also some risk to predators that may consume the dead voles. Proceed with caution, and always follow label directions.
I hate to do anything that harms the wildlife in my yard. But considering the information I've read about how quickly voles reproduce, and how they can wipe out a perennial bed in a season, they have worn out their welcome at my house. It may make me an ungracious host, but hopefully the word will spread in vole-world that the Nelsons are no longer providing bed and breakfast for the local vole population.