LOL, Laura your cat sounds like my Dusty! I broke handles off the plastic forks, stuck them prongs up in the mini planters....a few days later he's out there layin in the bed again... dont know how he moved those prongs, probably just clawed them out of his way
so thats when I kinda gave up LOL!
I have a zester, so I'll try the grounds and the orange zest and see what happens. I just dont want to plant anything more in there until I solve the kitty issue