i use cayenne pepper straight out of the bottle. i buy the large generic container. unfortunately, i do have to reapply after every rainfall... i use it mostly to keep seedlings, young and tender plants from being devoured before they get a chance.

I recently tried the following:
1 egg
1 teaspoon tabasco sauce
1.5 quarts (6 cups) water

Put in a jug, shake it up, then mist it over plants.
I've seen some fresh deer tracks in the yard since, but no obvious damage. I suppose it's too early to tell for sure if it's working, but I'd like to hope it is. And yes, I will have to reapply after every rainfall.

Before you buy some of the commercial deer repellants, look at the ingredients. Some list rotten eggs (under a fancier name) as the main ingredient ... might as well try the homebrewed version first, I figure.

I have heard that the ingredient in commercial preps that promise to last for 3 months (yeah, right) is Elmer's glue. I just planted out 30 baby firs, 15 yellow alaska cedar and a few shore pine, red flowering currant and indian plum. So I'm going to make up a home brew that's peppery hot and stinky. We'll see how Bambi doesn't like it.
June

My husband makes a home brew of crushed garlic, tabasco sauce, rotten eggs (yes, he lets the eggs get rotten first), and water. I wouldn't want to work with it, but I'm grateful all summer he does it. It really does work. We live within a mile of a national forest in northern Wisconsin and deer visit all of our neighbors, but for the last three summers, they've avoided our garden.

Brenda, VirginiaÂs brew sounds good enough to try (if not drink). I too have concocted something that works and does not readily wash off or deteriorate in sunlight. For 2 gallons of spray:

6 qt. water
2 1/2 cups Wilt-Proof (10:1 ratio with the water)
3-4 tbsp. HOT HOT hot sauce (why mess around?)
Spray all sides of foliage and buds. Do not spray on Sedum or other succulents. (Won't kill them but discolors them.)
And yes, I will add crushed garlic and rotten eggs this year)

To prevent clogging of the sprayer, I usually strain the mixture. Note that the hot sauces are oily, so I wash and scrub out my sprayer with hot water and Dawn. I spray every three to four weeks. It works.

But I have found a gadget that works very well, too. You might have seen them in catalogs pictured with decals (which I think are gaudy and don't use) to make them look like parrots. They hook up to a water source (which has to be open at all times) and are triggered by a motion sensor. I love watching the deer scramble when one of those goes off. Variable sensitivity settings (from Moose to raindrop); runs on a 9v battery all season. Dismantle before freezing weather; reassemble (easy) following year at new growth time. Unobtrusive and effective. Easy to turn off when working or walking in the garden.

Does't cayenne pepper straight from the bottle have too much salt in it? Isn't salt bad for most plants?
Is the concentration low enough not to harm the plants?

a rutgers university deer study (local university in our area) indicated that the commercial sprays that were the most effective deterrants contained a substantial portion of capsicum and eggs.

so i have a tub of chili powder and i use fresh eggs and mix it with water. but yes, unless you want to be going out there every time after it rains to spray everything again, i suggest adding some wilt-pruf ($6-7 for a regular spray bottle) to the mix to make it stick. i like that elmers glue suggestion though! maybe i'll try that this year.

the deer will generally nibble for a taste, decide they don't like it and move on, so you should be at least prepared for some small damage the first time they come into your yard in spring.