Still "thinking like a cat," let's consider something else felines are fussy about: the texture of what they step on. This is one way to use natural cat repellents, specifically, to keep cats from pooping in your garden. After all, it's not for nothing we have the expression, "pussyfooting around." I already mentioned chicken wire in this context on Page 1, but below I'll suggest a couple of materials found in nature.
Natural Cat Repellents Underfoot: No "Pussyfooting Around"
7. Cats don't like to walk on bristly material. So here's an idea: in mulching the problem bed, include something on which the refined paws of cats will fear to tread, such as sharp-edged pine cones.
8. Another mulch that functions as a natural cat repellent is stone mulch. It may not be the most attractive mulch for your particular bed, but cats prefer to poop in loose dirt. Cats usually won't bother with an area mulched in stone. They'd rather be "pussyfooting around" where the digging's easier on their paws.
Striking a Compromise: Grow Catnip, Make a Sandbox
In addition to the natural cat repellents suggested above, I had alluded to others on Page 1, including water, strong-smelling plants, and stinky substances such as dried-blood. But I'm going to change course for a moment and deal with some other methods for keeping cats from pooping in gardens -- methods that involve compromising rather than repelling.
As in landscaping with dogs, sometimes the path of least resistance provides the best solution to your problem. Strike a compromise with your cat by planting a separate bed of catnip plants, in another part of the yard. Not all cats go nuts over catnip plants, but those who do may come to view their "catnip patch" as their own private sanctuary and make it their new favorite hangout, thereby allowing you to keep your garden as your own sanctuary.
9. Better still, make a sandbox just for cats and keep it in close proximity to the catnip plants. Chances are that the sandbox will serve as a magnet for cat poop. Sure, you'll have to clean up the cat poop afterwards. But at least you'll know where it is.
How to Keep Cats From Pooping in Your Garden: Hi-Tech to the Rescue, Again
Hi-tech approaches to keeping cats from pooping in gardens don't stop with the motion-activated sprinklers mentioned on Page 1. You can also use ultrasound.
10. Ultrasound devices such as Cat Stop operate on a high frequency. It's inaudible to humans but unbearable for cats. Installation is easy. You simply situate the device so that it faces toward the garden. A motion sensor detects the intruder's presence, and Cat Stop then gives off its high-frequency sound, scaring off the cat.
Addendum 1: Why You Should Learn How to Repel Cats
The concern over how to repel cats is readily understandable and has nothing to do with whether or not one likes cats. Nor does it matter that much whether the cats in question are your own or someone else's. After all, it stinks to be working away cheerfully in the garden, only to end up stepping in cat poop! But the need for cat repellents goes beyond mere inconvenience. Cat poop can harbor pathogens harmful to humans. Ultimately, this is an issue of proper sanitation in the yard.
"But," you may protest, "the manure of barnyard animals is often used by gardeners. How is cat poop different?" Well, cat poop differs in one very important respect from, say, cow manure: the former is the product of a carnivore, not an herbivore. If your neighbor's cat is using your garden as a toilet, how do you know the cat's poop doesn't contain parasites passed on by its prey?
Addendum 2: What If I Compost Cat Poop First?
Nor is composting cat poop recommended, unless you're an expert in the science of how to make compost. Theoretically, you could heat the pile up enough to kill any pathogens in the cat poop. But you'd need to be very meticulous about it. For most people, composting cat poop wouldn't be worth the risk.