Cayenne pepper or liquid hot sauce as a deer repellent
There are many homemade deer repellent recipes that contain cayenne pepper and hot sauces, the one drawback is that they wash off when it rains or the plant is hit with a sprinkler. After that it is a race between you and your repellent and the deer: who gets there first. A quick internet search will get you all kinds of recipes. These are taste repellents which means the deer will take a bite before they understand they don't like it. If you have many deer this is a problem: that is a lot of "bites."
I personally prefer the commercial repellents: Bobbex, Liquid Fence, Plant Skyyd, etc. Most of these contain a surfactant that will not wash off with rain and will last 30-60 days. Most of these are a "smell" repellent containing a "rotten eggs" odor. They are organic These means that the smell repels the deer and they won't take a bite of your plant.
Deer are habit feeders; they have a set feeding pattern through areas where they know there is something to eat. They require so much green (5 pounds a day for a healthy deer) that they don't have time to go into yards with nothing to eat. The trick, then is to break the feeding pattern through your yard. It is my experience that the commercial products do this very well.
What I do is not only spray the plants but spray around them as well so as to create an area of odor that the deer don't like and therefore avoid it, They may still walk through, but they won't dine on your plants.
Believe it or not you can use the repellents in the winter. I sprayed my azaleas and rhododendrons during the last warm snap.
One other tip: start using the repellents early in the spring and keep up with the new growth.