Deterring feral cats

http://www.wildlifeanimalcontrol.com/straycats.html

Get a dog.

Fence in your yard and get a dog.

Cats hate citrus smells. Orange peels, shredded and spread where ever the cats like to hang might help. You'll probably need to reapply, but it's safe for your yard, and all the other critters.

I believe moth balls are supposed to deter them. Just put them in flower beds.

A fence and a medium or large size dog would be the best way to deter them other than getting them relocated.

Fence and dog.

I have the same problem. Cats dislike the smell of rue, and pennyroyal, Coleus canina and lemon thyme — so plant a few of these throughout the garden space. Lavender's my favorite. You'll get rid of the smell of your neighbors cats and things will smell much nicer.

Won't your local Animal Control help you catch the cats? I am a cat lover, but where I live you cannot allow cats and dogs to run loose. They must be contained in the house or in an enclosed area.