This month I wanted to discuss deer fencing.  This is a hot button for many growers because it is a complex issue that deals with an animal that creates strong feelings.

Deer do an amazing amount of damage this time of year.  Vines that have just gone through bud break can be damaged significantly.  New plantings are also especially susceptible to deer damage.  This is not the typical grape cluster damage we usually discuss, but instead, physical vine damage or stunting caused by deer feeding on new growth.  Unfortunately, a good year can be reduced to ruin before it even gets started with the help of what most people feel is a beautiful, warm and gentle animal.

On the West Coast we have Black-tailed deer and pockets of Mule deer.  On the East Coast the White-tailed deer is king, dominating some landscapes in such numbers that they are routinely topics of heated debates between the agricultural community and the state or federal regulatory bodies, under the ever watchful eyes of animal rights groups.  No matter which variety you have, the method of damage is usually the same.  Jump the fence, feed through the vineyard in the early morning and late evening or at night.  The evidence is present, the culprit is not.  So, how to fix, you ask (These animal control guys just run on and on about problems...)?

Several techniques are available for deer control.  There are age old remedies such as hanging bars of soap or spreading moth balls and garlic.  There is some new work being done with predator urine as an odor repellent (I can see the tasting room conversation now.... Ah, yes the 98’ late harvest Cabernet Blanc, it’s not the barrel fermentation per se, it was the uh, well, that was the block we used the mountain lion urine in... ).  Anyhow, these products may have some effectiveness, but there are better ways.

Deer are managed game species, so you cannot, will not generally, be able to do any lethal control of pest animals except during deer season, which won’t help you much.  The best method for the grape grower is fencing.  Deer fencing is available from several sources.  You may purchase metal fencing which will last longer that you can imagine or you may purchase plastic fencing which will usually last longer than you thought (5-7 years).  The key, however, is the installation.  Any properly motivated adult deer can clear an 8 foot high fence.  The trick then is to install it in such a way that they don’t want to clear it - you challenge their motivation. 

Deer jump fences the same way every time unless they are on a dead run, which isn’t what the’re doing if they are interested in feeding.  They approach the fence closely, possibly even touching it with their neck and chest, and then leap vertically over the fence.  If, during installation, you slant your fence away from the vines and toward the deer approach route, they will actually be underneath the fence when they approach to jump it.  This presents more of a physical and visual barrier than most deer are willing to negotiate (notwithstanding the deer being pursued by the aforementioned mountain lion with a bladder problem).  At any rate, this method of installation is very effective, especially when using the lower cost plastic fencing products (I’ll send you a copy of an installation diagram if you want it, wctmiket@qnis.net).

As with most animal damage control problems discussed here, there are usually several factors contributing to any given problem.  Perimeter cover, available food and water and so on.  But, given those usual constants, deer problems can be solved with fencing.  In fact, in some areas they can be substantially reduced with odor repellents.  Like a lot of pest species we discuss here, deer are not that smart, they’re just hungry and have more time than we do.  Good luck.