Try citronella, lavender, peppermint, lemongrass or orange essential oils
Try some of these tips https://www.craftylittlegnome.com/keep-cats-out-of-the-flower-bed/
Spray area with peppermint essential oil. Bugs don't like it either so it will be 2 for 1:)
here is a list of repellents you can buy.
I always say pepermint oil is perfect solution for that . Cats don't like that smell at all
Motion activated water sprinkler.
Clean the area with vinegar to remove the urine odor. Sprinkle cayenne pepper or chili powder around. One sniff and they'll remember. May need to reapply.
German Shepard in the yard. Electric fence in the pee areas.
I would find a motion sensor with lights or water to scare them off.
Hi Beth: What I use is those lava rocks. I put them down instead of mulch around my basement windows and in my flower beds. Cats, and most other critters, don't like to walk on them as it's not comfy on their feet. Also, if anything large, like a person, walks near your house on them at night, you will surely hear them :) Also, You can make a mixture of 16 oz of water and a 1/2 bottle of Oil of Clove or Clove Oil, same thing, in a spray bottle. Mix it well and spray it around your plants. It smells nice, but tastes horrible. It's non-toxic, so it won't hurt anything or any one, unless you put it in your' pets mouth. It's toxic if they eat it, but if they smell it, they won't be hurt. You can buy the oil at any candy making store or your local grocery store may carry it. It comes in a bottle about 2 inches tall and only costs a couple of bucks. Once the pet tastes it, they will give the area a wide berth when they smell it! Don't put it on your pet or in their mouths, it's toxic to them if they get more than a little lick. Good luck!