Beware the cat that likes to play in water--I had a cat many years ago that my dad would spray with a hose to keep out of the garden. But she decided she liked the water spray, and would follow him out there to get sprayed! Then he tried spraying leaves with hot sauce/water mix--also turns out she liked things spicy!
I'm sorry you have to deal with this. This is one of the many reasons I choose to keep my cats inside. It's not always easy. One of them tries constantly to sneak out when we open the door--the other got savvy at popping screens out of windows. But it's my job to keep a step ahead of them. I talked to my neighbor about it & told her my cats are strictly indoor kitties, so if they are out digging in her garden or something, to let us know right away. That's actually how we discovered the screen-popping cat--the neighbor saw her jump out of the window (I've now attached closures to all screens to hold them in place better) & came over to tell us. But it IS my responsibility to keep them under control. I don't want them pooping in other kids' sanboxes or in vegetable gardens, killing birds at feeders, or dragging baby bunnies out for the neighborhood kids to find dead--all things that I've had outdoor cats do.
As the arc of history bends towards justice, it's a new, more progressive day. --Steve Benen, The Maddow Blog, 11-07-12