Critter Problems - Common
Inevitably gardeners will at some point need to deal with the various critters that visit our landscapes. The same lakes, parks, trees and wildlife refuges that enhance urban life come with their own natural inhabitants such as squirrels, chipmunks, moles, voles and rabbits.
Outside of the city, not only do the gardeners need to deal with the same critters as urban dwellers, but they are also challenged for control of their landscapes by deer and gophers. For detailed information on how to handle deer and moles in the landscape, please refer to our information sheets entitled Dealing With Deer and All About Moles. Another companion sheet called Less Common Critter Problems offers information on dealing with bats, geese, ducks, birds, raccoons and snakes.
Before embarking on an all-out war against a critter, try to evaluate how much damage it is really doing. Sometimes the damage is just a passing problem or not significant enough to warrant taking control steps. There are several strategies and products that can be useful in dealing with critter problems in the garden. No matter how you choose to handle these problems, it is important to understand a bit about the critters' life cycle and habits. That will also help identify the critter if you didn't actually see it.
Our information sheet Repellents, Traps and Barriers can provide details on the products available at garden centers to help minimize or prevent animal damage to plants. Often the key to success in dealing with critter problems is to use more than one strategy or product and to make frequent changes so they don't figure out a way to circumvent your efforts. It also helps to encourage more natural predators.
If you have a persistent problem with animals damaging your plants you may want to contact the Department of Natural Resources to see if they can offer any additional information or help.
Description: The vast majority of squirrels that live within urban areas are eastern gray squirrels. Occasionally we see a few of the smaller red squirrels.
How They Live: Squirrels spend most of their time in or around trees. Squirrels are primarily herbivores. Their favorite foods are nuts (especially acorns, walnuts and buckeyes), seeds and grains. They are infamous for stealing food from bird feeders. Squirrels frequently bury extra food and dig it up later when needed.
Plant Damage: Squirrels often dig up plants while looking for their buried food, they dig and eat freshly planted tulip bulbs (and a few other minor bulbs), they nip branches off trees (deciduous and evergreen) for nesting and they may strip off chunks of bark for nests. They can be a serious nuisance at bird feeders, damaging the feeders trying to chew their way to the feed. Squirrels occasionally attack garden fruits and vegetables too.
Natural Enemies: Owls and hawks. Also dogs, cats and cars!
Repellents: Effectiveness varies. Try hot pepper oil, garlic oil or blood meal. You may have heard about using mothballs (naphthalene), but that is harmful to people, pets and the soil, and not very effective.
Exclusion: Very difficult; sometimes squirrels can be excluded by using a barrier of fencing, hardware cloth or chicken wire laid on the ground to keep them from digging. There are some good baffles available for bird feeders.
Chipmunks and Gophers
Description: Chipmunks (sometimes mistakenly called gophers) are ground-dwelling relatives of squirrels. They are small and easily identified by black & white stripes on their backs. Gophers are larger, brown ground dwellers.
How They Live: Chipmunks dig shallow tunnels in the soil, especially sandy soils. They consume mostly seeds and nuts but also slugs and insects and they love sunflower seeds. Gophers are mostly field dwellers, dig extension burrows and are rarely seen. They eat plants, seeds and insects. There are lots of chipmunks in areas of the city with sandy soils. Most gophers live in more rural, prairie areas.
Damage: Chipmunks will eat bulbs, tender root systems and root vegetables. Their tunneling may also cause damage to woody root systems. Gophers will eat plant root systems, but usually not garden plants since they are almost exclusively prairie animals. Both cause damage by their tunneling and mounds.
Natural Enemies: Owls, hawks and snakes. Plus cats and dogs.
Repellents: None is very effective, but options include castor beans, gopher spurge and whirligigs.
Poisons: Poison peanuts or other pelleted poison baits. Poison smoke bombs.
Exclusion: Almost impossible.
Description: Commonly called meadow or field mice, voles look just like mice but are stockier with a shorter tail.
How They Live: Voles travel in grassy areas creating shallow tunnels just barely into the soil. They also tunnel around in heavy mulch. They are omnivorous and eat mostly seeds, but they will eat bulbs and plant roots.
Damage: Tunnels appear as damage in the lawn in spring, but the lawns usually repair themselves. More damage is done when they gnaw on the bark of trees and shrubs during the winter when seeds aren't available.
Natural Enemies: Owls, hawks and snakes. Also cats.
Poisons: Poison pellets or grains are rarely effective.
Trapping: Snap traps like those used for mice can be baited with peanut butter and oats or nuts.
Exclusion: The voles can't really be excluded but trunks of trees and shrubs can be protected with wire ‘hardware cloth’. It also helps to avoid deep mulches and mulches with seeds. Minimize tall grass areas.
Description: There are six species of shrew in Minnesota and they vary in size from smaller than mice to the size of moles. They are gray-brown and have very pointed snouts.
How They Live: Shrews are insectivores with habits similar to their close relative, the mole, except they don't tunnel.
Damage: They seldom cause any plant damage because they are looking for insects, snails, slugs and mice!
Natural Enemies: Owls, hawks and snakes. Also cats.
Repellents: The research hasn't been done, but shrews may be repelled by castor oil like moles are.
Trapping: Traps made for moles may work.
Exclusion: Not practical.
Description: Wild rabbits range from 2 to 4 pounds and are grayish brown.
How They Live: They live in brushy areas, piles of branches and at the edges of yards with lots of cover. They use burrows for protection, especially during the winter. Rabbits are herbivores that will eat almost any plants, but they do have their favorites such as lettuce, tulips and members of the rose family.
Damage: Rabbits can do considerable damage eating young plants in flower and vegetable gardens, but the most significant damage is caused when they gnaw on the bark of apples, roses, crabapples and other woody plants during the winter.
Natural Enemies: Owls, hawks, coyotes, wolves and dogs.
Repellents: Animal urines, hot pepper spray, garlic oil, blood meal, products such as Tree Guard or Ropel.
Exclusion: Fencing and row covers are difficult to use, but can be effective. Protect tree trunks in winter by wrapping with hardware cloth.