What can I grow around the boundaries of my garden to hold out cats? Also how would cat owners feel if I allowed my dog to...

Also how would cat owners feel if I allowed my dog to come and do at hand business in nearby back garden?
Before you ask the inevitable yes I do verbs up after my dog when out for a walk which I other take surrounded by fields and not on public highway.
Answers:    i agree with you just about cats. Personally, i know people who have used small chunks of bath sponge soaked contained by fish oil, it swells contained by their belly and you don't see the cat again! But there are powders (garlic smelling) and pellet which act as a deterrent, but not really that devout. You could just agree to your dog out when you see the cat in your garden, they might capture the message then.
set up a live trap and pinch them to the pound