Cats seem to love to dig in whatever dirt they can find, including your potted plants. There are several things you can do to keep your cats out of your potted plants without resorting to toxic chemicals or standing guard with a squirt gun. The felines will soon learn to avoid plants that have an inhospitable soil surface and move on to other cat activities.
Spray your potted plants with products such as Bitter Apple or Bitter Orange. These are non-toxic sprays made to deter animals. While they won't harm animals, your cats will quickly learn that they taste really bad.
Sprinkle cayenne pepper on the leaves of your plants and all around the surface of the soil. Felines quickly learn to stay away from these.
Place dried citrus peels all over the surface of the soil. Cats have an aversion to citrus and will avoid plants where they smell it.
On the soil in the pot, put rose trimmings or cut-up stems from spent rose bouquets. Cats don't like digging around prickly things and will shy away from getting their paws poked.
Cut a piece of cardboard the size and shape of the pot. Cut a slit to the center and an area to accommodate the houseplant's base. Place the cardboard cutout directly on the soil. This is most effective for cats who don't eat potted plants but like to dig in soil.
Mulch the soil of the potted plants with rough-edged, medium-sized gravel. This will keep your cats from jumping into the pot and digging in the soil.