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Locally Grown: Deer Defense


IN ANY SOCIAL GATHERING WITH PEOPLE I know who don’t make a living growing vegetables, I’m invariably hit with a few gardening questions: What’s causing the dark spots on the lower leaves of my tomatoes? Some black-and-yellow insect is eating my zucchini. What is it? It’s October and my garlic is already up. Did I plant it too early? What do you do about woodchucks? They’ve eaten my kale.

Before the conversation turns to some other subject (like the weather or the troubled state of the Union), my answers usually are (in order): Probably bacterial spot or speck. Striped or spotted cucumber beetles. Better that your garlic not emerge before winter—try planting in November. Dogs, traps, guns.

These days, though, there’s one other question I’m hearing more frequently, the answer to which is more complicated: How do you deal with deer? (This is often followed by a list of what deer have recently eaten on the property and an even longer string of expletives.) Mostly, I offer a sympathetic nod, then ask if the individual has considered erecting a large fence.

The whitetail deer (Odocoileus virginianus) is well adapted to living amidst humans. Mature forest is not its preferred habitat—it thrives on disturbed land with plenty of new herbaceous growth, and many different kinds of vegetables, shrubs and flowering plants are very appealing, especially as winter approaches and less natural browse is available.

The deer population in the Hudson Valley is on the increase and has been for at least a couple of decades.

Deer appetites increase in the fall, since it’s imperative that they gain weight and build up fat reserves to carry them through the lean, cold months ahead. In winters with prolonged snow cover and access cut off to even a meager diet, deer can lose up to 30 percent of their body weight—if they lose more than this, they’ll likely die from starvation.

The deer population in the Hudson Valley is on the increase and has been for at least a couple of decades. Less hunting may be one of the reasons; milder winters, with less snow cover, another; subdivision of wooded and agricultural land may be a third. Thirty years ago, deer were not a major problem for us on the farm, except for occasional feeding on the edges of distant fields. Today, however, they’ve become a constant threat to many of our crops, and we spend an inordinate amount of time trying to thwart them.

One approach has been to grow more plants that they find unpalatable, like garlic, onions, shallots and certain herbs, but we already are maxed out on most of these. Our second (and main) defense is to try to exclude them.

Because deer are good jumpers, this usually involves creating a barrier at least 8 feet high. For a number of years, we’ve considered putting up a permanent, heavy-duty woven wire fence, which is what many vegetable growers and orchardists resort to. This would entail setting 4- to 6-inch-diameter, 12-foot-high posts into the ground every 15 or 20 feet, then tightly attaching 8-foot-high galvanized wire mesh. There would need to be, at a minimum, three or four sturdy gates for access in and out of the fenced area and at least a 15-foot swath between the fence and the crop rows for tractors and equipment to navigate and turn.

If we had one or two large, relatively level fields, a permanent fence (meaning it might last 20 years) probably would be our best bet, but our farm is a patchwork of small, sloping fields with lots of hedgerows, woods and wet areas. Given our uneven land, rocky soil and the challenge of setting posts 3 or 4 feet into the ground, the cost to fence just several acres could approach $30,000 or more, and such a fence would reduce our tillable area, be difficult to maintain and, to my mind, would mar the natural beauty of the land. (I’ve always had a soft spot for the old Cole Porter/Robert Fletcher song from Adios, Argentina: Give me land, lots of land under starry skies above/Don’t fence me in.)

So, instead of a heavy duty, permanent fence, we’ve gone with temporary barriers that we keep in place for about eight months each year. To 1-inch-diameter, 10-foot fiberglass rods set 2 feet in the ground, we attach 8-foot, heavy-gauge plastic netting using spring clips and cable ties, holding the netting tight to the ground with 8-inch ground stapes. (This prevents deer from getting under the fence, but not necessarily woodchucks, which are capable of chewing a hole in the plastic mesh.)

For good measure, we run a line along the tops of the poles and tie on old white row-cover flags every 10 feet or so—these flags blow in the wind and are usually quite visible, especially at night. We also periodically soak the flags in liquid that has an offensive odor to deer—Deer Stopper (made with rotten eggs and rosemary) and Plantskydd (made from dried and powdered bovine blood) work reasonably well. These visual and olfactory repellents provide added deterrence. We get all our fencing supplies from an outfit called Kencove in Blairsville, PA.

Another temporary (or seasonal) fencing option is to use braided electric twine or half-inch electric ribbon attached to fiberglass rods. In this case, instead of creating a physical barrier to prevent deer from entering the fields, a sharp electric shock, preferably to the nose, sends them running in the opposite direction. Such fences usually employ two or three strands of twine or ribbon, at about 2, 4 and 6 feet above ground level (about where a deer’s inquiring nose is likely to be). This strategy calls for small pieces of tinfoil, smeared with the cheapest peanut butter available, wrapped tightly around the twine or ribbon every 6 or 8 feet. Ideally, a deer, attracted by the odor of the peanut butter, will make contact with its nose and receive a sharp electric smack.

The fence itself is relatively easy to put up and take down. The braided electric twine or ribbon can be dispensed from a spool and rolled up when no longer needed. The fiberglass rods need to be no more than a half inch in diameter (except on the corners, where thicker rods add stability). The electric twine or ribbon is attached to the fiberglass rods with wire clips. Of course, this type of fence requires a 110-volt outlet or a portable solar-powered generating unit. We’ve used braided electric twine and ribbon fences in the past and probably will again, especially when pinched for time, despite a few drawbacks: Deer may eventually learn to jump over them; deer can inadvertently knock them over; and weeds or grasses that make contact with the braided line may cause the electric current to short, rendering the “fence” essentially worthless as a deterrent. (To avoid this, weeds and grass growing under the fence line must be trimmed repeatedly.)

Earlier this year, one or two deer managed to breach our net fence near a wooded area and enjoyed several meals of sugar snap and snow peas, greatly reducing our supply for market. After walking a few thousand feet of fence line, we found the compromised section and repaired it. A few weeks later the same animals (or some of their brethren) ate the tops off a few hundred young tomato and pepper plants in an unfenced field. We halted all other farm work and rushed to put up a temporary fence to protect the remaining uneaten plants.

If you’re thinking all this sounds a bit complicated and demanding—it is. However, if you’re in the vegetable-growing business, having most of your crops eaten by deer is a lot worse. Deer are beautiful animals that were on this land long before we showed up. The challenge is how to co-exist with them and grow vegetables for market at the same time. Obviously, we’re still working on that.

Hudson Valley Restaurant Week is back this April 8-21!