Do this to prevent voles from eating your garden
Q: Can you tell me how to prevent voles from eating my garden. They have eaten the roots and entire plants of my lettuce and bok choy plants. I also think they are causing damage to some of my landscape plants. It appears that they may have taken over some old gopher tunnels, is this possible? I have never had problems with voles before but I am positive it is voles causing all these problems because my cat caught one.
A: Vole numbers tend to fluctuate from year to year so gardeners that have not had a problem one year will report being overrun the next year. They are prolific breeders with the peak breeding season in the early spring. Voles are mostly herbivores, eating grasses, bulbs, tubers and herbaceous plants. They typically eat roots and bark in the fall and winter. They can damage a wide variety of landscape plants, vegetables, and will even girdle fruit trees.
I have not heard of them taking over gopher tunnels but many times voles will have numerous small openings (1-1 ½ inches) in the ground, often with visible above ground runways through the grass or weeds. Typically, there isn’t a lot of dirt pushed up around the tunnel openings, as is seen with gophers and moles.
There are six species of voles in California; however, the one doing damage to your plants is most likely Microtus californicus. Voles are also called meadow mice, but shouldn’t be confused with the typical house mouse. Voles are approximately 5 to 8 inches long, including their short tail. They are mouse-like; however, they have small eyes and partially hidden ears. Voles are active year-round, both day and night, although mostly at night.
To discourage voles from entering your garden keep grass and weeds mowed short. Voles don’t like to feed in the open, so keeping grass and weeds cut low, or removed, will limit habitat. Consider a cleared strip around your vegetable garden to discourage movement. You can also protect some of your plants and trees with hardware cloth or makeshift collars — open-ended plastic jugs, milk cartons, etc. — buried an inch or two into the ground to keep them from tunneling in.
Trapping is the recommended control measure. You will need about a dozen mouse traps for a typical yard/garden. You can lightly cover all the tunnel openings with soil. When voles have reopened the hole, you will know this is an active tunnel. Place the traps at a right angle to the runway, near the opening of a burrow. You can choose to bait with peanut butter/oatmeal mixture or leave them un-baited. The voles run along their runways and will trip the mousetrap.
It is important to check the traps daily and move them to different runways as needed. Destroy old runways and burrows with a shovel to keep voles from moving to this area. If you have dogs, cats or children that might trip the trap, you can cover the traps with tubing, rain gutter, etc. in order to keep paws and/or fingers out of the traps.
Read more from Master Gardeners:
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Baiting is another control measure to eliminate voles and can be effective for large areas but is not recommended as the baits can be poisonous to pets, children and wildlife. If you do choose to bait, take precautions to protect loved ones and wildlife and please follow the directions on any baiting products.
The use of repellents, such as castor oil, and fumigants are questionable as there has been no scientific studies that have shown they effectively work for controlling voles. More information can be found on voles at https://bit.ly/2QfxDlk.
The Shasta Master Gardeners Program can be reached by phone at 242-2219 or email firstname.lastname@example.org. The gardener office is staffed by volunteers trained by the University of California to answer gardeners' questions using information based on scientific research.