find a butcher shop and ask them if they have any blood they can sell you, idk tell them your going fishing for catfish and you use it to make bait(this actually works btw lol), throw it around the plants, maybe leave a note telling them. "I know you know. Don't even think about it." they'll probably lay off, imo that would scare the living shit out of me. lol
Also, some traps being setup is a good thing. Like a basic pitfall or something take this for example, dig a bunch of 3 foot wide holes about 4 feet deep, put a bunch of broken glass in the bottom, and cover it with some sticks, and leaves and see if you catch anything
you can google how to make snares too, instead of using a rope to catch a leg try using some barb wire, its a bit nastier. theres actually alot of gurilla traps that can be made and alot of them are simple, if you do a bit of research I'm sure you can come up with something good.
That fishook thing mentioned earlier is a good one too. if you do use the fish hooks make sure you get treble hooks not regular ones, treble hooks have 3 prongs. And also make sure to use some brush to cover them where you can, a dumbass trying to steal wont care about brushing a few plants on his way to rip someone, he just wants to steal, which makes it all the better.
I'm pretty stoned right now just so you know, so I really can't say how good of an idea any of this would be for you, it might just be me being high...but yeah....lol