Introduce the dog to the cayenne pepper. Fill the palm of your hand with the pepper and walk the dog toward the flower bed. As you approach the edge of the bed, hold the cayenne directly under the dog’s nose.
Give the dog a discouraging command, such as “no flowers,” and walk him away from the bed. The dog will learn that the tingle of the cayenne paired with the negative command means the flower bed is a bad place to play.
Dust a layer of cayenne pepper around the perimeter of your flower bed. Sprinkle it over the soil, coating the ground with a thick, even layer of powder. Cayenne pepper is extremely potent and causes nasal irritation, deterring the dog from exploring your flower bed.
Mix 1 oz. of cayenne powder with 12 oz. of water in a spray bottle and spritz it over leaves or stems hanging over the edge of the bed. If the dog mouths the leaves, the bite of the hot pepper will remind her to stay out of the flowers.