Neighbor's Cats Using Planter as Litterbox

Sprinkle cayenne pepper. Needs to be done after each watering.

Move your gravel out of the way or lay chicken wire on it. Use scissors to cut space for your plants. Cover with more of your gravel. When the cats dig to go potty they will step on the wire. They can't stand walking on it!

Keep it wet. Cats don't like to dig in wet soil. Spray with something that smells like citrus. Cats don't like citrus. Get a big squirt gun and shoot the cats with it. They don't like getting wet at all. Put a cage of chickenwire over it. Put little trays of ammonia around. That's something else they don't like to smell. Moth balls are poisonous and not recommended especially if you have children who might think they were candy. Good luck!

Pea gravel won't deter cats as they think it's cat litter. Either use larger size gravel or just add large stones or decorative shale to the the original gravel in the planter. I've tried this and it does work. Good luck.