Preventing Deer Damage with an Electric Fence
If there is a way deer will go over, under, around, or through an electric fence so they must be very tall and low to the ground also.
Preventing Deer Damage with a Baited Electric Fence
This is a lot better than a plain electric fence because the deer will touch the baited wire with its nose rather than jumping over. See Baited Electric Fence
Preventing Deer Damage with Tall Fencing
The ultimate defense is tall, sturdy, wire deer fencing. If built properly a traditional deer fence is 100% effective for preventing deer damage. An impenetrable deer fence must be sturdy and at least 7 feet tall and staked down at the bottom. Deer fencing of any kind is prohibited in many areas. Conventional deer fencing will make your house look like a stockade. See Deer Fence
Preventing Deer Damage With Deer Netting
Deer netting such as that sold by Benner's Gardens has many problems associated with its use: Deer can become entangled in netting. Benner' Gardens deer netting requires support, either posts like a conventional deer fence, or it has to be supported by your plants. If Benner' Gardens deer netting is laid on your plants it will push them down and destroy much of their natural beauty. When your plants grow up through Benner's Gardens deer netting it cannot be removed without destroying your plants. Rolls of Benner's Gardens deer netting are heavy. Benner's Gardens deer netting is not made in the US. http://wirelessdeerfence.com/benners.html
Preventing Deer Damage With Homemade Or Commercial Organic or Chemical Deer Repellents
Deer deterrent spray-on products taste bad and smell bad to deer (and humans). Some of these deer deterrents are toxic and carry manufacturers warnings that the product is hazardous for humans, pets and waterways (e.g., Havahart Deer Away). If you make your own spray deterrents it can be less expensive: there are many recipes on the Internet. Common ingredients for spray-on deer repellents are rotten eggs, garlic oil, hot pepper oil, soap, and fish oil. Some of the commercial deer repellents also contain glue to make them stick better to the plants. Continuous reapplication is required. Other stinky things used to prevent deer incursions into your yard are blood meal, predator urine, predator feces, milorganite (sewage sludge), rotten eggs, and other foul stuff. These products are really nasty; I would rather have the deer. Predator urine is collected under the most inhumane of conditions, it is ineffective and should never be used. A more esthetic spray-on deer deterrent can be made from liquid Irish Spring, 5 Tablespoons/Quart of water.
Preventing Deer Damage With Noise Makers
Deer are smart, adaptable creatures. They soon realize noises won't hurt them. After all, deer will commonly graze along a busy highway. Propane exploders, which go off at random intervals may be effective but often for just a short time.
Preventing Deer Damage With Big Mouth Billy Bass, Motion Activated Lights, And Other Motion Activated Mechanisms
Motion activated mechanisms and lights will certainly startle the deer. They will also startle the forgetful gardener and the neighbors. Deer are used to living around humans and they become accustomed to these mechanisms when they realize there is nothing noxious about them except the sudden motion, sound, or light.