Lisa - How sad indeed. I also work at a school that has become an environmental school. We have greenhouses, raised garden beds, etc. I've always thought that there really isn't anything on school grounds or even my front yard to stop plant thieves. You'd be surprised at how often such incidents happen.
Years ago, I remember someone on one of the forums somewhere (I can't remember which forum anymore), but they grew, sold, and traded some particular plant species. Well, they had a plant thief who came and stole a large amount of their potted plants in the middle of the night. Needless to say, the owners were so upset! I can imagine.
That is one of the reasons I do not put really nice or rare plants (that could easily be dug up) in my front yard. If it isn't bolted down, it seems to be fair game these days. It's criminal. I am amazed that people will go onto private property or community property and do such a thing! Sickening.
to Lisa!