The Deer Wars
Does coyote urine scare away the gardener's 150-pound scourge?
Gardeners can learn to weather drought and hail, burning heat and killing frost, even transient insect attacks. But it's harder to adapt to 150-pound hoofed creatures tearing at your plants. In the battle of man vs. deer, passions run high. To score a victory, it may even seem reasonable to cloak your garden in the scent of a creature that could tear a deer limb from limb.
Which explains why people go to garden centers and hardware stores and pay good money for a bottle of coyote urine. (Marijuana growers who don't like fences are especially gung-ho.) Particularly when enraged, gardeners tend to fall back on mystical thinking and become perilously vulnerable to anecdotal evidence and advertising copy. But for all its atavistic appeal, predator pee disappoints. Hungry deer get used to practically any deterrent. The best ways to fight them off are far less exotic.
We, not the deer, started the conflict over gardens, and fairly recently. In the 18th century the great British garden designers—artists like Humphrey Repton and Capability Brown—directed their lordly clients to array deer on the lawns of their country homes in order to add life to the landscape. But those were the days when a legion of servants was on hand to handle deployment. Now, as we build mini-Georgian mansions and neo-Colonial second homes on land that was once exclusively deer habitat, we have fewer underlings around for animal control—and a lot more deer.
Deer that don't get knocked off by cars (the predators that have taken over from wolves and coyotes) show a particular fondness for some of the most beloved and costly garden plants and flowers—apple trees, rhododendrons and azaleas, tulips and roses. Suburban gardeners often considerately plump up their plants with fertilizer, making them all the more tender and nutritious compared to the tough, thorny stuff in the woods.
The manner in which deer eat our tender greens inspires particular outrage. They have incisors on the lower half of their jaws; the top jaw is only hard gum. * So, they don't just nip rhododendron leaves or rose buds. They wrench and rip them. (Rabbits and other rodents do tidier pruning work with their opposing sharp teeth.) How thrilling to fight off the gnashing deer by making use of its highly developed sense of smell and taking on a fanged predator's qualities as your own—all by way of an 8-ounce bottle of pee that costs $22.99. To appeal to that human instinct, ads and labels usually feature a close-up of a coyote face, beautiful and sinister.
Coyotes are clever and adaptable, but hardly known for being cooperative. So, how do the purveyors of pee get their product? Working back from a retailer (Yardiac Garden Store) to a middleman (Wetsel Seed Co. in Harrisonburg, Va.,) I came to a wholesale source: Bill Graham of Leg Up Enterprises in Lovell, Maine. Graham believes he's the predator-urine baron, claiming control of 90 percent of the U.S. market. (The U.S. Department of Commerce doesn't keep track of market share. Neither does Bloomberg News.) Graham says he gets his pee in keg-party-sized barrels from 10 facilities he doesn't want to say much about. To those who worry about the health and happiness of his canine producers, Graham offers this reassurance: "The urine is collected from animals that are kept on farms and zoos. … The urine is collected passively. The animals are not aware that it is being collected. They are conditioned to use an area of their habitat for urination, and the urine drains into vats and is filtered and strained." He also claims that "the animals must be in good health and fed well in order for the urine to be effective as a territorial deception scent."
To use coyote urine to fool deer into thinking a predator is lurking, gardeners are supposed to hang a bottle with holes in it filled with urine-soaked cotton balls in trees or posts around the vulnerable plants. Alternatively, they can spray the urine directly on the plants. Graham concedes that urine repellent won't work all the time. He advises using urine early in the season, before the deer have developed their feeding patterns.
The Web site of the Wildlife Damage Management Program of Cornell Cooperative Extension concludes that coyote urine "may be effective when deer damage is at low to moderate levels." But the evidence is all anecdotal. One of the few tests even approaching scientific rigor was done by Tom Seamans, a Department of Agriculture wildlife biologist. (The Federal Aviation Administration, which has a strong interest in keeping deer off airport runways, partly financed the study.) Runways are fenced, but Seamans wondered if predator scents could create a sort of chemical fence to keep deer from passing through any holes. He set up two piles of corn, one unscented and the other surrounded by wicks emanating essence of coyote urine. The deer at his Ohio field station went after both piles of corn with equal enthusiasm.
What deer-control tactics are more consistently useful? Seamans' method for his own vegetable garden is a German shorthaired pointer and a 16-year-old beagle. Most professional nursery growers say that for zero deer damage, erecting a 10-foot fence around your garden is the only way to go. Consumer Reports enthusiastically endorses a motion-activated sprinkler, called The Scarecrow, that delivers a 3-second burst of water. But the sprayer patrols a limited area and can't be used in freezing temperatures. And it might also change your garden karma by zapping dogs, children, and guests. Some gardeners swear by concoctions of rotten egg and rotten fish. You have to apply these bad-smelling and -tasting agents again and again during the growing season, as healthy plants put out new growth.
In the end, as is so often the case in the backyard world, the most successful gardeners are observant, flexible, and willing to be humbled. They might note that deer are hungriest in winter and especially likely to find domestic edibles when the snow begins to melt. As a result, it's wise to put netting around fruit trees and the ornamental shrubs until there's plenty of spring forage in the forest. The wise gardener might also favor plants that deer don't like and human beings do: Daffodils instead of tulips, thorny roses rather than refined hybrids, and the perennials catmint, achillea, salvia, foxglove, lavender.
Constance Casey is a former New York City Department of Parks gardener and writes the monthly "Species" column for Landscape Architecture Magazine.
Photograph of woman gardening by Ed Suba Jr./KRT; coyote on Slate's home page by David McNew/Newsmakers.