>>507234393 (OP)I'd build a trench about 10ft deep around it disguised by the garden, there'd be a jet of water at the bottom turns on from a pressure plate when the vandal falls to the bottom, this then conveniently slides them into the woodchipper that is used to make dog food for a pack of 12 hungry rottweiler's used to deter any further nogging of the area.
Realistically, what I would do is build a pond in the middle of the garden, put a fence up and have a flock of swans living between the plants as protection, they can break arms so if they're stupid enough to climb inside it becomes a real fight for their life, 24/7 livestream it to twitch to fund repairs to the garden and feed the swans.