First let me start by saying that I DO NOT mean to offend anyone!

I seem to have a cat problem in my back yard. They keep pooping on my flower beds. When I dig in the dirt I find their poop!! Very disgusting!!
I know the majority of these cats belong to neighbors.

Any suggestions? Is there any plant the will repel them from my flower beds?

Well, I own a cat (indoor one though) and I hate them using my yard for a toilet and a trysting spot. To get woken up at 2 a.m. to infernal wailing is aggravating.

Hot pepper flakes; Critter Ridder and the like are pretty good at making garden areas off limits, but they have to be reapplied after a rain.

Many use a strong screening, buried an inch under the soil. Plants grow through the grid, but digging by cats is difficult. It takes a lot of work to install, not to mention the possible costs.

The best success I've had yet is orange essential oil. You can toss orange peelings in the garden, and back them up with 50% orange juice, 10% orange essential oil, 30% water and a few drops of liquid soap. This will make an oil stain on anything it it sprayed on, so watch out around wood decks.
Orange oil, when sniffed or ingested orally makes a cat salivate quite a bit, and this is offense to them. Orange on the rear end will sting, but no lasting damage.
Orange essential oil is relatively cheap, and I also use it to scent my linen closet, which the indoor cat will get into if the door is open.
When we first got the new puppy, the cat took to taking a pee or poo on my little DS's bed, marking territory I think. I washed his Spider Man bedding with a cup of orange juice in the water and added a few drops of the essential oil to the rinse water and dryer sheet. Problem solved.
Make sure it is pure essential oil, not a fragrance type. Only the real thing will work.

p.s. Dogs don't care much for orange either.

Thank you LoamLump!!

I will try the essential oil and the hot pepper flakes.
The orange essential oil? Where can that be purchased?

A little more explanation on the hot pepper flakes, please. (the ones with seeds and all?)
Please advise.
Thank you.

Essential oils should be at your nearest health food store. Up here, orange costs around $7.00 for a quality, aromatherapy grade. Do not buy mandarin orange - it doesn't have near the same effect, but lemon, lime and grapefruit are good substitutes.

Hot pepper flakes. The kind found in any spice rack or Italian restaurant. Just use straight from the bag (buy at a bulk food store). Boost the effect by adding ground black pepper and sprinkle dry around your garden.

You can chop up some habanero or other hot fresh peppers, say three or four in a quart of water, add a drop or two of soap for added stick. Test the strength on a leaf or two and wait a day for any reaction from the plants before spraying the whole lot.