Just as aphid season is slowing down, a larger pest problem raises its lovely head; think Bambi! What do you do to prevent deer damage?
Deterrents are the best deer-management option. These include fencing, chemical or electronic deer repellents and scare tactics. The best deterrent, fencing, has high initial costs, but those costs may be offset over time and fencing provides the longest-lasting results. Chemical repellents sometimes work, but you must reapply them regularly for them to be effective. Devices that scare the deer can provide temporary relief from deer damage, until the deer get used to them.
Many brands of chemical repellents are commercially available. Deer either dislike the taste of the product when they munch on the treated plants or the smell drives them away. Electric fencing can be programmed to shock deer, which then learn to stay away. There are also battery-operated electric devices that you bait to attract deer. These then shock them, conditioning them to stay away. Scare devices that incorporate motion or noise can be used to frighten deer from yards, crops and gardens. You can hang metal pie pans or cans around plants.
Mylar tape twisted into a spiral, and suspended between posts, makes a buzzing sound when the wind blows over it, which can help discourage deer. Motion-activated ultrasonic noisemakers scare deer using high-frequency sounds that are inaudible to humans, and don’t violate noise ordinances.
Other noisemakers may violate noise ordinances or disturb neighbors and may not be appropriate for use in town. Deer are adaptable and quickly overcome their fear of most of these devices. Field trials of various scare devices indicated deer become habituated to them after a week of exposure, so be wary of manufacturers’ claims of long-lasting results. Motion-sensor devices that are only activated when they detect a deer close by are generally more effective over longer periods. Active, barking dogs can keep deer away as well.
If you have found a way to prevent or reduce deer-caused damage, let me know at skellyj@unce.unr.edu or 775-887-2252.