To keep your cats out of your potted plants there are a few solutions you can use. One solution is to cover the top of the plant with aluminum foil as cats will not climb on it because they are afraid of or do not care for the texture and sound it makes. Another solution to keep your cat off your potted plant is to cover the soil of the plant with medium size unmovable pebbles or rocks the cats will not be able to dig down and will not find it a comfortable place to potty. Another idea is to put something that is unpleasant smelling but will not hurt your plant in the soil because a cat will sniff around and check out the area before it potty’s there so if you put something like say crushed red peppers or mothballs in the area it will possibly detour the cat from using it to potty. You might also take a look at your litter box and see if there is something wrong with it like is it too dirty and your cat wants to potty in a clean area. Cats are particular about where they potty so it might be as simple as keeping your litter box cleaner or changing the type of litter you have.
There are a few ways to stop cats from using you house plants as a litter box. Grind leftover citrus peels in a food processor and spread them on the soil of your flower bed. Also you can spread tea leaves or blood meal on the flower bed. It has a terrible odor which will keep the cats away. Also, you can try to spray a commercial animal repellent on your plants. They contain the urine of predators and scare cats away,
I've never had that problem however I have heard cats do not like the smell of coffee grounds and pepper.. Put a good amount(up to u how much the more the better) of either one on the top of the soil(do not mix) they will repulsed by the scent
Buy little citronella tea lights and stick one in each pot. If you have a large planter they are using as a litter box, place the tealights 12-18 inches apart. Cats and dogs don't like the scent and will stay out of your potted plants.