You can repel dogs and other pets from off-limits areas of your home and garden by making repellents from citrus, vinegar, ammonia or cayenne pepper. Each of these substances is completely pet-safe, repelling the pet through unpleasant odors.
To keep dogs out of your garden, place fresh slices of orange or lemon throughout the area periodically. Alternatively, spray your couch with a lemon juice and water mixture to keep it pet-free, or keep a glass of lemon water nearby.
Ground cayenne pepper mixed with black pepper is an effective repellent for outdoors. For a stronger repellent, soak coffee filters in ammonia or vinegar, cut them into strips once dry and place them where you want to repel pets.