One GUEST said that many of the things recommended here are CRIMES against the cats in question. Damn right! Specially the minefield and the moat full of piranhas that I recommended...It's all really quite upsetting, and it's incredible to me that people would actually be cooking up nasty schemes to drive off cats. Few things add the grace and beauty to a garden that a cat does...stepping lightly among the flowers, cleaning her fur whilst lying in a sunbeam, etc.
Cats are cool. A garden can always be improved markedly by the presence of a cat.
Admittedly, there are some cats who are slovenly or troublesome in nature, but they are in a minority, I find. Most cats are attractive and entertaining.
Do cats restrict your movements? No. I say do them a similar courtesy, and don't restrict theirs.
- LH