Whether it is a stray, a neighbor's or your own, when a cat decides it likes your flower garden for naps or as a litter box, you need to do something--and fast. There are many commercial products available that have mixed reviews as to their effectiveness. But you can use things you probably already have around the house to repel unwanted cats from your flower garden.
Push plastic forks (tines up), chopsticks or twigs into the soil every 6 to 8 inches throughout the open areas of your flowering plants. Creating an annoying, bothersome area for cats can keep them away from your flowers. An abundance of pine cones spread in your garden also works well.
Spread a thick layer of rough wood mulch, rock or pebbles around the flowering plants. Not only will this make the soil in your garden unappealing and inaccessible to cats, it also will help retain moisture in the soil, which benefits your flowers.
Plant rue in several places within or along the perimeter of your flowers. There are several other plants often suggested for repelling cats, such as lavender, but the rue plant is among the most effective. The rue plant has an odor cats avoid. Rue grows 2 to 3 feet high, has gray-green foliage with clusters of small yellow flowers, and thrives in USDA zones 4 to 9.
Spread pieces of citrus peels--oranges, lemons, limes or grapefruits--through your flower garden. The pieces can be large or chopped. Like rue, cats do not like the smell of citrus rinds. You will need to continue spreading citrus rinds or peels every few weeks since it will decompose over time.
Spray the wild cat with water, either from your garden hose, sprinkler or a spray bottle. A few water baths, and the wild cat will soon decide to find somewhere else to spend its time. You can also connnect a motion-detector system to a sprinkler, but it will also get any other passersby wet.