Green Horizons

There is a potential problem in paradise! Deer have become so abundant that weed control alone is no longer sufficient to ensure good tree growth and a bountiful nut crop. Foresters have always preached that good weed control will result in better tree growth … and it’s true! In agroforestry, we continue to preach this message with an even broader application. Many of the agroforestry practices involve opportunities to harvest multiple tree crops. While agroforestry practices may involve the harvest of timber, this is often in addition to annual crops such as nuts and fruit. In order to maximize the vigor of our trees and facilitate harvesting, it is then necessary to manage weeds in these practices. One of the nut trees we believe has real crop potential throughout Missouri is the chestnut (Castanea mollissima). Most of the currently recommended chestnut cultivars are of Chinese origin and offer measured degrees of chestnut blight tolerance. However, should your chestnut trees be so fortunate as to produce a heavy crop, you will most certainly only be looking for leftovers after the deer have eaten their share. So, what can you do? After covering several options for controlling nuisance deer, I’d like to share with you a solution used effectively by Sen. “Kit” Bond (pictured above with his orchard’s guard dogs) to keep deer out of his chestnut orchard.

If you’re putting in a tree planting that requires the use of high-dollar planting stock, or an investment of your valuable personal time (such as an orchard using grafted stock, or an orchard requiring you to do the grafting), then you will want to protect that investment. There are several methods available to limit the likelihood of loss to deer. However, there are none that are 100 percent foolproof. Some of the popular methods rely on repellents. There are a variety of commercial repellents available, or you can mix your own. Most repellents rely on two methods of deterrent, smell and taste. However, no matter which repellent you choose, there are drawbacks. For example, (1) if purchased, they can be expensive; (2) many are water soluble and must be reapplied following rain events; (3) most will need to be periodically switched as deer become familiar with a product’s (or formula’s) odor; and (4) in general, most repellents should not be applied to fruit destined for consumption by humans (there are a few compounds labeled for use on edible crops – be sure to read labels carefully).

A second option is to use scare devices. However, most scare devices, such as a propane gas canon, use noise to scare animals and might also annoy neighbors. Scare devices also have been shown to be only temporarily effective. Animals tend to grow accustomed to the sights and sounds, and are no longer frightened away.

Fencing is a third option. Should you consider fencing? Deer are high jumpers, and a fence must normally be at least 8 feet tall and extend to the ground in order to exclude them. There are numerous designs available, including both electric and nonelectric, with a wide range of costs. One of the biggest challenges that one faces with fences is maintenance. This is especially true when using electric fences. When deer begin penetrating fences it is often due to a lack of maintenance. This can be the result of breaks in the fence structure, or vegetation lying across the electric fence, grounding it, which essentially turns portions of it off. Many times deer will not see a fence, and as a result of running into it, will break through. When using electric fencing, a popular method of alerting deer to the presence of the fence is by baiting them. By placing peanut butter on aluminum foil and wrapping it on the electric fence wire, deer are attracted and, when their curious nose and tongue receive an unwelcomed shock, quickly learn that the area is to be avoided. Aside from the fact that some people don’t like the appearance of a large fence, fences, when maintained, can be a relatively effective deterrent to deer.

A compromise between conventional fencing and scare devices is to use dogs. However, most of you will immediately recognize that one of the short comings of this method is keeping the dog in the designated area. And, if you tie the dog, this will limit its ability to chase the deer away. This past fall I had the chance to visit an orchard owned by chestnut grower Sen. “Kit” Bond and saw a very nice nut crop being guarded by two of the friendliest dogs you’d ever hope to meet, unless of course you’re a deer. For a number of years, Sen. Bond has shared his chestnut crop with a local Boy Scout Troop and cadets of the Missouri Military Academy who helped him harvest, and of course his resident deer herd. From what I saw this fall, in the future more of his crop will be going to local causes and less to the fattening of his deer herd.

Powered by a 12-volt, rechargeable, deep cycle marine battery, an invisible dog fence has been placed around the 3-acre Bond chestnut orchard. The fence is composed of a buried electrically charged wire that transmits a radio signal to special dog collars which warn the dogs as they approach the orchard boundary. The dogs, rescued from a local humane society and specifically trained to stay within the orchard boundary, wore collars which, as the dogs approached the perimeter fence, emitted a warning sound that only a dog could hear, and then administered a static shock if the dogs proceeded and got too close to the perimeter fence boundary. Prior to being turned loose in the orchard, the dogs underwent extensive professional training to recognize the warnings associated with the buried electric fence. The dogs had a house and were fed and watered on a daily basis by a local caretaker. The result: very few deer ventured into the Bond Chestnut Orchard, and those that did, didn’t stay long! An additional benefit was no fence interrupted the visual appearance of the orchard. The only sign of a “fence” was one plastic container which kept the battery and transmitter out of the weather.

Is this solution for everyone? Perhaps not. However, when high value crops (such as chestnuts that can bring $3 to $7 per pound) need protecting, this is one solution that is effective, aesthetically pleasing, and reasonably priced. All of this and the dogs are nice company too.