[PCT's Annual Wildlife Control Issue] Yes, Deer!

Odocoileus virginianus, a.k.a. whitetail deer, have long been the arch nemesis of many pest management professionals and landscape contractors in suburban and rural areas. For years the war has been fought between man and beast on battlefields of lush manicured sod and flowing hills of both native and exotic plants.

TOO MUCH OF A GOOD THING? In 1909, New Jersey estimated that less than a hundred herds of whitetail deer existed throughout the entire state. Now, New Jersey reports more than 160,000 herds that share this tiny state, many of which roam areas heavily populated by people. Much milder winters, suburban garden buffets, lack of predators and the inability of man to hunt the whitetail in heavily populated communities are all compounding factors leading to negative economic impacts and a potentially dangerous environmental situation.

A conservative estimate for nationwide deer damage as compiled by the Cornell Cooperative Extension Service soars in the $2 billion range. About $1 billion is a direct result of incidents involving automobiles, while the other $1 billion comes from more than $100 million in agricultural crop damage, $250 million in ornamental landscape damages and more than $750 million in damages to the timber industry. The Cornell Extension Service also notes that it is often difficult to put an exact number on estimates regarding wildlife-related damage. Many times the reported numbers a far lower than actual damages.

With regards to the environment, in many woodland areas, whitetail deer are responsible for completely eradicating some species of wildflowers from their native habitats, and so extensively damage the natural understory growth in forested areas that some native birds are losing important feeding and breeding habitats. Even chipmunks, squirrels and other woodland rodents are in competition with deer for acorns, nuts and berries. Who would have ever thought of Bambi as some type of woodland bully?

And then there is Lyme disease. Yes, undeniably whitetail deer are a favorite target of the insect Ixodes scapularis, commonly known as the deer tick. However, a recent study performed by the New Jersey School of Medicine and Dentistry showed the most prevalent species responsible for the spread of the disease is the common white-footed mouse, which like the whitetail, also heavily populates America from coast to coast. Deer mice are the principal reservoirs of infection that carry the bacteria, which causes Lyme disease. Juvenile ticks feed on mice, contract the bacteria and set out into the world using the whitetail deer as their primary source of transportation and nutrition. When humans of a sporting or gardening nature share the same spaces as the deer, we too also become a feeding source for the tiny arthropod assailants.

DEFENSE WINS GAMES. So, how can pest management professionals help homeowners with this four-legged pest?

First there is fencing (in its many incarnations). There are hundreds of fencing solutions to deter whitetail deer from entering homeowners’ gardens but only two completely effective means of fencing to keep deer away from plants entirely. The first method is to erect a fence no less than 8 feet high along the perimeter of the yard or garden plot. (Whitetail deer have been measured jumping vertically up to 15 feet.)

There are several manufacturers of reasonably priced fencing materials that are suitable for this specific purpose, but you must approach the project as sort of a long-term investment as these undertakings can reach into the tens of thousands of dollars to install. Second, a series of fenced-in plots that include tops to completely enclose horticultural livestock can be installed. Neither of these fencing solutions need be altogether unattractive, but the more elaborate or "invisible" the fencing design becomes, the higher the installation price rises.

Next on the list of whitetail defenses is the use of repellents. Most repellents are either taste repellents or odor repellents and they can be either organic or chemical. The author has noted highest success with a bi-weekly application rotating between the two types. The two most popular repellents on the market are Hinder (chemical) and Deer-Off (organic). Another notable repellent is Deer Solutions. This product is also a reliable deterrent for keeping away these woodland pests. Repellents work best if applied liberally, or as directed on the label in the case of chemicals, before the damage has started. If it rains shortly after your application, most would agree that all bets are off.

Furthermore, during a drought or after a tough winter, desperate deer are prone to eat just about anything, sprayed or not; for them it is a matter of survival. It is important that a homeowner and pest management professional select the proper repellent for gardens (i.e., be mindful of vegetables or fruit).

Another category of deer defense that is only sometimes effective is scare tactics. Dogs are often used to deter deer and other vermin from gardens. Dogs mark their territory leaving an unmistakable odor for the deer and other animals that clearly warns them to stay away. Some dogs can be trained to chase away deer and some dogs just genetically love to terrorize any creature that steps on to your property. Although largely effective, dogs also have been known to lazily lounge around in the warm sun just watching deer and other critters parade across their owner’s garden quite unmotivated to do more than watch these four-legged assailants feast.

Noise makers and strobe lights are effective for the first week or so, then deer not only become accustomed to the distractions but seemingly regard them as only a small distraction on the way to their next meal.

Finally, the most effective form of defense against deer is to suggest to homeowners to use "the right plant for the right place." Suggest your customers plant deer-resistant materials in their gardens every time they plant, and they may notice the deer are going to their neighbor’s house to eat more often.

The author is a landscape design and construction consultant and owner of Eclectic Exteriors Landscape Designs, Cedar Grove, N.J. He has 12 years experience in the green industry and can be reached at jgruen@pctonline.com.