Ah! I usually get into trouble for this but my granfather used to swear by gorse clippings taken from the common (briar or berberis works as well). Cats have very sensitive pads and they soon learn to go elsewhere. You do need chain mail gloves when weeding though! There's all sorts of other deterents from lion poo to water pistols. Pepper sprays and such usually only work untill the first drop of rain.
There have been so many threads on this ..... !! I suggest you do a search and see all the topping advice that has been given. However, never being able to resist being a know-it-all!, my special favourite is "Silent Roar" which is pellets soaked with lion's urine! You can just imagine the little also rans taking one sniff and thinking "Jeepers - not going to mess with their cat!". I found this page off another forum you might like to check out. On there someone says it's a waste of time but a couple of folk of my immediate aquaintance swear by it .... each to his own, I suppose!
