There is nothing I despise more than deer. I wrote a post a couple years ago, while Vinny was out of the country, about the ways I was keeping deer out. Those guys will jump over fences, go through the smelliest sprays, and do anything to eat those hard earned greens. It can be so incredibly frustrating finding your veggies eaten down by some animal. This year, we have a few different strategies that has been incredibly effective and I wanted to share. Hopefully you will find that these work for you as well.
Keeping our dog out in the yard. This is not 100% effective but it definitely can do the job to suddenly scare a deer away. It is best when the dog is not kept back by anything, the deer will learn quickly that the dog is not going to chase after them if a fence stops the dog.
Building an "invisible" fence. By using fishing line and poles, you can create an "invisible" fence around your plants that will be cheaper than creating an actual fence tall enough to keep out the deer. String the fishing line two to three feet above the ground tight around poles, once deer comes close, they will become confused or think something has touched them and get scared off.
Making a scarecrow. Our scarecrow, affectionately named "Frank
the Tank", has certainly scared us a few times (we are constantly thinking someone is standing in the pasture, definitely leading our dog to bark at times too). This scares away deer thinking that a human is there. We used old clothes and stuffed with straw.
Additional idea
Install a motion sensor sprinkler system. Something about getting sprayed in the face unexpectedly will definitely deter a deer from chowing down on your veggies. Keep in mind, this would not be great for winter (pipes freeze, would need to be drained and stored properly).
Hope this helps you keep those hard earned veggies this season and maybe even give you some ideas to keep out other pests as well!
Here is a picture of our hard working (but mostly goofy) dog!