How do I stop cats from trampling my flowers?

I have tried everything , orange peels, pepper, cayenne pepper, chilli powder, curry powder, spray i bought from a pet-shop everything. I then got a very large syringe from my daughter, i fill it with water and have sprayed the cat with the water quite a few times. Seems like that has helped. My neighbour have bought a large cat made out of metal and she has that in her garden and says it is working but i still see that darn cat around. If you find a good solution, let us know, thanks.:)