[clkeiper]

ummm, blackberries will literally become a thorn in your side. they will spread and pop up far away from your border. My neighbor has them for a fence row around his property but they encroach into the area where we grow corn. they are an awful pestilence when walking the edge of the field. they pop up out in the field... they are probably going to annoy you as much as deter trespassers. but it is totally up to you what you want to eradicate at some other point. blackberries are an excellent barrier plant. Black raspberries are easier to manage and I would think pretty effective also. but no matter what you put there you have a lot of work to do to keep them corralled too. string wire and make a trellis for them to look more as if you are using the boarder then trying to annoy the neighbors. game cameras will also help deter trespassers if you can put them up and call the sheriff when there is activity of littering ... I know we can use them as evidence for prosecution here.

you can transplant any of them right now.all you have to do is get a sharp shovel and cut them out of the ground. there should be plenty of small ones to work with. if you choose to use what you have to work with from the other plants you already have. I hate blackberries so much I would never plant one on my property.

and put up no trespassing signs... just small unobtrusive ones... no need for making waves if at all possible. but maybe the neighbors will appreciate someone trying to clean it up and make it a nicer place.