Managing the Six Worst Garden Animal Pests

Hungry dear chewing on plant
Hungry deer will eat practically any garden plant, especially in scarce winters.

Gardeners beware, the enemy is among us.  Operating by stealth, they wait for opportunities to transform our gardens from points of pride to scenes of devastation.  They eat our cabbages and sweet corn, destroy our hostas, and root up our tulips.  They are ravenously hungry and untroubled by human scruples.

Little raccoon in the garden
Raccoons are cute, but they can quickly damage fruit and vegetable crops.

Who are these enemies of horticulture?  They are the worst animal pests that plague our gardens, and even if they don’t frequent your place yet, they are most likely hard at work in your neighborhood.

The list of “Six Most Unwanted” may vary a bit, depending on geography, but most gardeners agree that deer are at or near the top.  Rabbits are right up there, followed by groundhogs, and in some locales pocket gophers, squirrels, chipmunks, voles, or raccoons. Here are those that we deem the worst:

  1. Deer: These four-legged eating machines will mow down everything from your hostas to tulips, winter trees and shrubs, and most anything in the vegetable garden. Their size can make management most pricey, often calling for high fencing to keep them from the plants they like to eat.
  2. Groundhogs: Roly-poly groundhogs can quickly devastate vegetable gardens, fruit patches,  and their large burrows are a yard and garden nuisance.
  3. Rabbits: Just like Peter in Mr. McGregor’s vegetable patch, these hopping herbivores will nibble on garden flowers as well as vegetables undoing plantings in a blink of an eye.
  4. Voles: Voles are root and tuber eaters that will consumer tulip bulbs in winter and chew on root crops, such as carrots, beets, and radishes in the growing season. They are known to use mole tunnels to consumer roots from below.
  5. Raccoons: Raccoons often raid vegetable gardens and fruit patches, making away with ears of corn, berries, and fruits of all kinds.
  6. Squirrels: Fruits and seed heads may be attacked by squirrels. They tend to do their most garden damage during dry periods, and in fall when they are saving food for winter.

Managing the Worst Garden Animal Pests

To keep our gardens beautiful and productive, we gardeners must pit our large brains and opposable thumbs against animal pests driven by constant hunger and a biological imperative.  The battle is sometimes hard fought, but we can at least hold our own by using intelligent management strategies.

Fence ‘Em Out

The best way to stop all kinds of critters is with appropriate barriers.  For deer, the barrier must be tall—at least 8 feet—so that the animals can’t jump over it.  Some of the most durable and expensive types are made of metal.  They are quite effective, but may not blend into the landscape.  In suburban areas, local ordinances may prohibit tall fences and the price tag may make them impractical for large gardens. Tall, polypropylene mesh fencing is less obtrusive and expensive, but it is also less durable than metal options.

Rabbit in the garden
Rabbits are most destructive early in the season when plants are small.

Electrified deer fencing does not have to be as tall, but it can be a problem in high traffic areas, especially where children and pets are likely to be present.  “Invisible” fencing, similar in concept to the type used to contain dogs, works via special electrified posts that can also be baited with favorite deer foods.  Deer that approach the invisible fences get a mild shock that acts as a deterrent.

If rabbits are the problem, a low, electrified fence, with wires positioned at 2 and 4 inches above the ground may offer a solution.  A non-electrified fence made of chicken wire can also deter Peter Rabbit’s relatives, but it should be 4 1/2 feet tall, with 3 feet above the ground and another 18 inches of fence buried underground to prevent the bunnies from burrowing below.  Before burying the underground portion, bend the bottom 6 inches so the bent strip of fencing forms a 90-degree angle with the upright part of the fence.  The bent strip should project outward from the upright section.

Groundhog among flowers
Groundhogs are destructive and their large burrows are a hazard!

Groundhog barriers are similar to those for rabbits, but require a 30-inch underground section to deter the burrowing animals.  As with rabbit fencing, bending the bottom and top 6 inches of chicken wire at a 90- degree angle projecting outward from the vertical portion of the fence will likely convince voracious groundhogs to look elsewhere for dinner.

Barriers will also stop gophers, and should be sunk into the ground to the same depth as groundhog fences, but need only be about 12 inches high.
Squirrels make distinctive messes in gardens, digging indiscriminately, uprooting plants, and stealing ripe vegetables.  If the garden area is relatively small, enclose it in a secure cage made of chicken wire, hardware cloth and/or bird netting.  This may also stop raccoons, but the furry bandits are both smarter and more dexterous than squirrels.  Any cage arrangement designed to keep hungry raccoons away from your tomatoes and zucchinis should be well secured and sturdy.

Repellents

Vole in the garden
Voles will damage roots, bulbs, and tubers.

If barriers are impractical, too expensive, or too obtrusive, spray vulnerable plants or areas near them with one of the many repellent formulas on the market.  Most are made with ingredients like egg solids, capsaicin and/or predator urine scent and will often deter many different types of varmints.  Always read the label directions carefully, wear gloves and protective clothing, and stand upwind of the area to which you apply the compound.

The downside to deterrent sprays is that most must be reapplied after every rainstorm.  Some animals also accustom themselves to the compounds after a time, so it’s a good idea to switch up products on a regular basis.  Noxious smelling mixtures should not be used on parts of edible crops that you intend to eat, such as fruits, but they may help save ornamentals.

Squirrel on metal barrier
Barriers will not keep squirrels away. Repellents work best. (Image by Tduk)

Some gardeners use homemade scent deterrents, and recipes for those concoctions are easy to find.  Others swear by the deer repellent properties of scented soap hung from trees or fence posts in affected garden areas.  Bags of human hair can be employed in the same way.
The presence of a dog or even sometimes a cat may deter pests when the marauders are faced with your pets or the smell of your domestic animals’ distinctive scent signatures.

Plant Resistant Plants

Hollies
Deer resistant plants, like hollies, are good landscape choices where deer are a problem. (Image by Jessie Keith)

If pest animals are a fact of life in your garden, you probably use a combination of strategies to combat them.  One good one is to grow vulnerable edible or ornamental plants in a single area and cordon it off with barriers.  Use the rest of your garden to grow plants like foxgloves, daffodils, lavenders, and other plants most garden pests don’t like.

Many plants that repel deer and other four-footed pests are strong smelling and/or somewhat toxic. Many deer-proof plant lists exist, and they include plants that other animal pests don’t generally include on their menus. One of the best lists is the Deer Resistant Landscape Plants List offered by Rutgers University.

Strategies to Avoid

Some frustrated gardeners also use traps (live or lethal), poison, or other physical or chemical means to dispatch animal pests.  Before taking that route, be aware that lethal trapping may be illegal in your area, and poisons can be toxic to pets and desirable wildlife in addition to the intended targets. Children can also be harmed by poison baits, and they may even pose potential harm to the person administering them. So, err on the side of safe and smart when it comes to animal pest management. A yard and garden can be protected without becoming unduly harmful to the environment.
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About Elisabeth Ginsburg


Born into a gardening family, Elisabeth Ginsburg grew her first plants as a young child. Her hands-on experiences range from container gardening on a Missouri balcony to mixed borders in the New Jersey suburbs and vacation gardening in Central New York State. She has studied horticulture at the New York Botanical Garden and elsewhere and has also written about gardens, landscape history and ecology for years in traditional and online publications including The New York Times Sunday “Cuttings” column, the Times Regional Weeklies, Horticulture, Garden Design, Flower & Garden, The Christian Science Monitor and many others. Her “Gardener’s Apprentice” weekly column appears in papers belonging to the Worrall chain of suburban northern and central New Jersey weekly newspapers and online at http://www.gardenersapprentice.com. She and her feline “garden supervisors” live in northern New Jersey.

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