How to keep cats out of my flower box?

I solved the same problem by placing old thorny rose bush canes in the place the cat was using. This is time to be pruning roses so if you don't have any, maybe your neighbor does. Any thorny stems will do.

Sprinkle cayenne pepper or chili powder. One sniff and the cat will remember. May need to reapply.

put pieces of chicken wire on the top of soil cat won't walk on it or dig to go-- Cayenne pepper does not keep cats from digging because they are not aware of its presence until after the fact when they leave the area and clean themselves burning eye,nose,genitals ,nipples/babies if nursing; no need to be cruel to cat with cayenne because owners are irresponsible and let it free roam to go in others yards----Article--Several months ago my anal-retentive, elderly neighbor dumped cayenne pepper in an area of her yard that my cat apparently had chosen to use for her toilet.Instead of contacting me to help her figure out a way to stop my cat from being a nuisance, my neighbor took to the Internet and read all about dumping pepper on the ground to deter cats. I ended up spending more than $350 on vet bills when my cat suddenly became quite ill with what appeared to be a bladder infection. Urination was so painful for her that she would just lie on the ground in the backyard and cry. In addition, she was constantly licking her back paws and chewing her claws to get out the pepper, while sneezing over and over.

I didn't connect her symptoms to pepper poisoning until my neighbor explained her problem with my cat.

Cayenne pepper does not keep cats from digging because they are not aware of its presence until after the fact. The best method for neighbors who have problems is to communicate with the pet's owner. My neighbor has since placed wire mesh in the area and covered it with topsoil and decorative rock. That makes us all happy.