The cats have been at it again so the sonic device and curry plants aren't working. I don't want to use chili powder anymore as I have now read it hurts the cats pretty badly.
Next options are mothballs, but they are toxic.
Or to keep the ground wet which may be good for keeping cats off but may kill the plants.
On the plus side, the garden is looking better now it's planted with flowers. I'm going to get some more so that there are fewer patches of earth for the damned beasties to dig up.