Most dogs will find something else to chew on besides your plants if you apply a distasteful spray or sprinkle of cayenne pepper to the leaves.
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Dogs sometimes eat plants when an essential nutrient is missing from their diet. This knowledge may be small comfort to the gardener facing defoliated decorative plants when the household canine goes from carnivore to herbivore. If your dog acts like Agent Orange in the garden and putting up a fence just isn't feasible, try these simple steps to modify your dog's behavior. Your methods include positive reinforcement and leaving a really nasty taste in the mutt's mouth.
Say "no" in a firm, sharp voice when the dog chews on plants. Sniffing plants doesn't count.
After you scold the dog for eating plants, praise the dog when it moves away from the plants.
Consult a veterinarian about possible diet supplements or a different type of dog food to dissuade your pet from eating the backyard flora.
Buy a bottle of bitter apple spray, available at pet shops and big-box retailers.
Apply the spray to plant surfaces just before you let the dog outside. The taste will discourage most dogs from dining on plants sprayed with bitter apple.
Sprinkle powdered cayenne pepper on leaf surfaces if bitter apple spray is unavailable. Cheap cayenne pepper is available in plastic shaker bottles at the local dollar store; there's no need to pay top price at the supermarket. When your dog tries some spiced plants and beats a hasty retreat to the water dish, you'll know the cayenne is working. Most dogs won't eat plants spiced with cayenne pepper more than twice before they get the idea.
Make a 50/50 mixture of hot sauce and water, and pour it into a spray bottle. Spray the plants with the pepper sauce. This may last longer on the leaves than dry cayenne pepper, which is useful for stubborn dogs that might acquire a taste for cayenne.
Consistency is key. Always remember to praise your dog for positive behavior and to speak firmly in an admonishing tone of voice when it misbehaves.