How can you animal-proof your garden with cayenne pepper? The easiest way is to just sprinkle it around the base of the plants you are trying to protect, as well as around the entire border of your garden. You can also create a spray using 2 tablespoons of cayenne pepper for every one gallon of water. It is important to note that if you do use cayenne pepper in your garden, it can also cause coughing and temporary blindness in animals. If you are looking for other natural ways to keep pests at bay, there are plenty to try.