Although you cannot train cats to overcome the instinct to hunt or turn a patch of soft soil into a litter box, you can use plants that repel cats to enhance your garden and to keep them away from places where they are not welcome.
Also known as Scardy Cat, Coleus canina has a strong smell that repels cats and other animals. The National Gardening Association suggests creating a hedge with Coleus canina plants spaced about 3 feet apart around flowerbeds, sandboxes and other areas where cats are unwelcome.
Among the herbs that repel cats are citronella, lavender, rosemary and chives. Cats should stay away if you plant them as a border around your flowerbeds or intersperse them among the other plants in your garden.
Although rue repels cats, it is toxic to people if ingested and can cause skin irritation if touched, so plant it with caution.
Cats will not like rubbing against prickly plants, such as cactus, if they are interspersed among the other plants in your garden.
A Garden for the Cats
A separate bed of catnip and catmint will give cats a happy alternative to your vegetable garden and flowerbeds.
Toxic to Cats
Although mothballs and mothball flakes are often used to keep cats away from gardens and bird feeders, they are toxic and can contaminate the soil. Stick with natural deterrents.