1.

Cats are sensitive to smell and dislike many scents.  Choose one or more of the following and scatter it around in the areas you wish to keep the cats out of: coffee grounds, pipe tobacco, cayenne pepper, orange/lemon peelings, rags soaked with perfume or dried rue (an herb sold in health food stores).

2.

Push disposable wooden chopsticks or 10-inch plant stakes into flower beds every 8-inches to prevent cats from digging or scratching.

3.

Spray cat repellent (available at pet supply stores) around the perimeter of your yard and along the top of the fences.

4.

Purchase a motion-activated sprinkler that sprays intruding animals.  One such model called the Scarecrow is available at 1-800-767-8658.

5.

Obtain an "ultrasonic" cat repellent by calling 1-800-762-7325.