DEER FENCE HEIGHTS, TYPES,
March 16, 2022
Deer Fence Height
Deer fence height is a major issue that we discuss in detail elsewhere. However, the main conclusion of careful Department of Agriculture research is that few panicked white-tailed deer will leap a 7-foot fence. Also, our own experience of over 20 years with mainly 7-foot fences is that non-panicked deer seeking food will not jump a 7-footer. Therefore, it seems reasonable to conclude that nothing more than 7 feet is needed.
Deer Fence Uses
Like deer fence height, deer fence uses vary a good deal. Because of the large U.S. deer population (roughly 30 million at last count), various kinds of deer fences have come to play a major role in protecting selected places (gardens, yards, vineyards, orchards, farms, airports, and even stretches of vulnerable highway) against deer. In general, these fences are more reliable, maintenance-free, and longer lasting than lesser measures like repellants, ultrasound devices, and water sprayers. And even though they can be quite expensive, where reliable control is needed, deer fences have become the preferred tool. Therefore, its worth taking a look and the range of uses to which deer fences are put.
In general, deer fence types include high-tensile fences (those installed under high tension), electric fences (boasting just a few wires and a fence charger instead of barrier fencing and tall posts), and various sorts of barrier fences not installed under high tension (including ones using polypropylene, metal hexagrid, and welded wire fencing, typically with a fence height ranging from 7 to 8 feet). Just as one should not normally play football in tennis sneakers or tennis in bedroom slippers, anyone planning a deer fence should know enough about the various kinds to select a type suited to the job. Therefore, it’s worth taking a moment to review these different kinds of fence and the tasks to which they are typically applied.
This term applies to any fence installed under high tension. However, high-tensile fences used to keep out deer typically employ “fixed knot” fencing with heavy galvanized steel wires forming a wide mesh joined by little metal knots. Fence height is typically about 8 feet. Such fences, though costly, work well on large farms with flat fields where reliability and low maintenance are sought. They can also be used to protect deer-prone stretches of highway where the fence can be set to run straight for a long way and the land is pancake flat. However, these high-tensile fences handle grade changes poorly and require massive (and expensive) braces capable of offsetting some 2,000 pounds of pull at every corner, end, and gate. They also look ramshackle and perform poorly if not installed under high tension. Therefore, they are not suited to short distances, fence plans with many changes of direction, or sites that are not flat.
Electric Fences: Deer Fences Used to Protect Crops
These take a wide range of forms, the one we especially like having only 3 runs of wire mounted on 2 lines of thin fiberglass posts – the outer wire being 3 feet above ground and the inner wires (3 feet back from the outer wire) being at heights of 2 and 4 feet. Such fences are typically baited, and the bait needs to be refreshed periodically.
In general, fence height is not a major issue because electric fences are a psychological barrier. The deer can run through them if they choose; and if the power fails or the fence is grounded by weeds or a fallen branch, the deer will soon learn to ignore it. Therefore, electric fences have the reputation of being less than 100% reliable and requiring high maintenance, their main advantage being low cost. These fences are used mostly on farms, because homeowners don’t want electric fences around their yards or gardens; highway planners don’t find them suitable for protecting roads; and the owners of orchards and vineyards generally want greater reliability than they offer. However, where 100% reliability is not required, they can provide a good cost-effective answer.
Plastic, Metal Hexagrid, and Welded Wire Fences; Fence Height 7-8 Feet
These are the deer fences, typically with a fence height of 7 to 8 feet, that are installed to protect gardens, yards, estates, orchards, and vineyards. Not installed under tension, the low-visibility black fencing is drawn taut manually and mounted on posts spaced 10 to 20 feet apart. These posts can be round black steel posts, angle-iron posts, studded steel T-posts, wooden posts, or trees. In cases where plastic fencing (the cheapest type) is used, the plastic should be strong, with a breaking strength of at least 650 pounds per foot. Also, it should be supplemented with a 2-foot bottom barrier of metal hexagrid fencing at all sites where rabbits or woodchucks (aka ground hogs) are present. That’s because these animals will chew small holes in the plastic fencing – holes that the deer will then discover and enlarge to penetrate the fence.
Bottom Folds, Ground Stakes, Brace Bands, and Earth Anchors
Regarding barrier deer fences not installed under tension, a few other points deserve mention. First, deer don’t really want to go over a tall (7-foot or taller) fence. They want to go under it. The best way to prevent that is to fold out some 6 inches of the fencing at the bottom (meaning that in creating a 7-foot fence one should start with fencing 7.5 feet tall) and stake this fold down every 6 feet with a foot-long ground stake. This arrangement effectively ends the problem of deer getting under the fence.
Second, especially when dealing with fences over 200 feet long, corners, ends, and gates should be braced with earth anchors (or more cumbersome and expensive brace posts) to counter stresses coming down the fence. This is especially true of fences in places with heavy snow.
Finally, for those using round metal posts, your fencing can tend to slide down those posts. Therefore, it’s worth getting brace bands (one for the top of each post) to provide anchor points that prevent this.
None of these small items (ground stakes, earth anchors, or brace bands) adds significantly to the cost of the fence, but all significantly improve its performance.
Jonathan Leonard, Manager
McGregor Fence Company LLC
Deer Fence Uses: Further Reading
Bekaert Corporation. Fixed Knot Brace Specifications and Installation Guide. https://sasteelco.com/assets/SolidlockBraceSpecs2013small-pdf.pdf
Freeman, L. Electric Deer Fence Tips and Resources. Blog post. National Center for Appropriate Technology. https://www.ncat.org
VerCauteren, KC; VanDeelen, TR; Lavelle, MJ; and Hall W. Assessment of Abilities of White-Tailed Deer to Jump Fences. U.S. Department of Agriculture, National Wildlife Research Center, Staff Publications, No. 1342. 2010.