I'm posting this here in case it will help anybody else. Whether or not this will work, time will tell.
I live in a very green neighborhood, for which I am grateful. It soothes my soul to see the great tumble of leafy trees with thick shady branches, flowering in season, lush landscapes, tall hedges, all of the urban wildlife inhabiting the green world, the squirrels, birds, butterflies, ladybugs and bees. Some say we have raccoons around here too, but I've never seen one. I used to see possums all the time but I haven't seen one in a few years. I used to smell a skunk now and then, and in 2015 our handyman told me to, quick, come outside and look at something. When I learned he was leading me to a family of baby skunks under the building, I went back inside. Didn't want to risk the revenge of an upset mama skunk.
And then the cats. The explosion of our stray cat population is probably why I don't see possums or smell skunks anymore. Every spring we have adorable kittens at my building. Everybody gives them treats and leftovers, but one lady makes sure they have food and water every day. Currently we have eight strays, well fed but always hungry, and as cats have the biological imperative to do, they terrorize the birds and squirrels anyway. The same lady who feeds them, paid out of her own pocket to have five of the eight "fixed".
An aside is that we have big ugly roaches in this neighborhood. I never had them in my own apartment, because I don't leave food out, until 2017 when we had a three day hard rain, and suddenly I had a roach invasion. I got rid of them by putting down boric acid, and haven't been troubled since then, but you see them outdoors any time. Yuck.
One year I had a mouse, but only that one time. My landlady had a professional service come and do whatever mouse controllers do, to the whole building, and I haven't had that particular problem again, besides which, I'm sure the cats have everything to do with the disappearance of mice.
The third current is the destruction of the garden outside my front windows, a long planting bed which, after the "stormageddon" of February 2021, was left full of big dead brown plants. The sago palms on the other side of the walk survived, but the garden in front of my windows was mostly dead. I removed the dead plants, down to the one plant still thriving, which was a nandina that started as a volunteer, and was still lush and green, with winter berries on it. Since the one volunteer was doing so well, I planted a few more nandina spaced apart. From June 2021 until now, they have remained the same size, small starters, but they still looked healthy and green, until they started looking sad, with spots that were not typical of their coloring, showing obvious distress. One day I noticed the soil was scratched away from them in piles, leaving the plant bases exposed. With my hand I started to sweep the soil back toward the plants, and that was when I noticed it. Cat turds. Tons and tons of cat crap all throughout the garden. It will be the cats' preferred toilet area, since they don't like to be around sago palms. I don't understand why they don't use the huge tall bamboo grove next to the driveway, but you can't discuss these things with cats.
It's up to me to take care it. The landlady is oblivious to garden issues. So I researched online what to do. I didn't want to use poisons. I'm trying what I hope are some good discoveries. Orange peels repel cats. They don't like the smell. Also you can leave oranges out indoors without attracting pests. Roaches and ants don't like them either. Wow. I already knew you could leave out garlic. It repels roaches. It turns out, garlic repels cats too. Coffee grounds in the garden also apparently repel cats and roaches.
So I'm eating a lot of oranges now. I chop the peels and spread them out on the soil. It's going to take some time to really fill the soil with enough peel to make a lasting difference, but I keep at it. I also put down tons of raw garlic. I just break up the bulbs, don't peel them, just throw down the cloves. Some will probably take root and send up garlic plants, which is fine with me. I'm throwing down my daily coffee grounds. Finally, cayenne powder, sprinkled liberally over the soil and the plants, works for a while, but animals adjust to it and eventually it will stop deterring them, so I sprinkled out two 4 oz. jars, and will probably repeat the cayenne only once per quarter, to keep that tolerance from developing. I also read you can stick skewers in the soil, and the cats won't take a chance on getting their feet poked. The bamboo skewers are pretty cheap, 100 of them for a a buck at the dollar store, so I spent a morning sticking 200 skewers in the soil.
Fingers crossed.