Deer fences are often found surrounding vineyards in the mid-Atlantic, where I’m located. The fence represents a large capital cost for materials and installation. However, many growers complain that the fence does not exclude all vertebrate pests that consume grapes or browse on green tissue in the vineyard.
This leads me to believe that many vineyard fences do not successfully match the vineyard and the risk for fruit depredation at a particular farm. Here are most of the criteria that should help a grower determine how much fence they need, if any.
The primary role of most vineyard fences is to exclude deer from the area and crop inside the fence. Deer can and will browse on the green tissue of the grapevine, particularly in the late spring and early summer.
The injury caused by this browsing is quite problematic when training young grapevines. However, deer are capable of infiltrating most deer fences by jumping over the fence or finding a suitable gap to slink through.
Depredation of ripe or just under-ripe fruit before harvest is often a more grave concern for vineyard managers. The grapes grown in vineyards are an excellent food source for many wild pests — including raccoons, groundhogs, bears, oh my — that are difficult to exclude from the vineyard. Many of these small vertebrate pests can climb, burrow, or otherwise infiltrate many vineyard fences.
In some cases, the fence is used to keep other pests — people, such as tasting-room visitors — out of the vineyard.
I don’t hear growers talk about being satisfied with the efficacy of their fencing choices. Instead, I hear complaints or the need for additional temporary deterrents to be added at periods of peak pressure. Examples of these temporary deterrents include motion-sensing scare devices and temporary electric fencing at hot spots.
Headlands and Access Ways
The primary role of fences around vineyards is to exclude pests, however these attributes of a fence hinder movement of equipment, people, and fruit in and out of the vineyard. Gaps are necessary in the perimeter fence for such movement. Building gates to have the exclusion capabilities similar to the rest of the deer fence comes with material costs as well as making the gates more cumbersome to open and close.
Headlands of 30 to 40 feet are not uncommon when trailered equipment is moved though the vineyard frequently. This headland will increase the linear feet of perimeter fence needed to exclude pests from the vineyard.
Material Costs and Durability
Vineyards are long-term perennial cropping systems. Fence materials durable enough to withstand many years in the field are more expensive than those designed for a shorter service life. This is important because failed fences do not exclude pests from the vineyard and replacement of fence materials and repairs increase the cost of the fence.
Cellar Door Appearance
The goal is a durable fence that will last a long time and exclude pests from the vineyard. The fence should also look good; this is especially important for operations that rely on direct sales from the farm. There are many beautiful rural landscapes that are complemented by a quaint fence line, but when it comes to direct marketing for a luxury product, most wine tourists wish to see a well-kept fence.
On the other hand, fences with excellent exclusion capabilities may conjure undesirable associations such as a jail yard. Barley visible, or at least sharp and handsome fences are desirable to enhance wine tourism.
All the Factors Together
In sum, deciding on a vineyard fence is a long-term decision and deserves quite a bit of forethought. How much pest pressure will be present is one of the most important variables that can be very different from site to site. This is a tricky balance between breaking the bank with an expensive deer fence and spending a modest sum for the necessary level of exclusion needed at a particular site.
Thinking through how the fence will influence vineyard and harvest traffic is important. For example; is the fence designed in a way that a truck and trailer can enter, turn around, and exit the vineyard during harvest? If direct farm sales are part of the plan for the enterprise, take the time to consider how the perimeter fence looks to consumers.
In some situations, with little pest pressure, a modest or even no fence may be justified around the vineyard. In other situations, with lots of pest pressure, say next to a large wooded lot, a handsome yet effective fence may be necessary. The point is that there is not a one-size-fits-all solution to fencing around a vineyard.