I like to do both maps and labels, and still sometimes they get messed up. Photos of the beds helps too. When one shows up in a strange spot, I put twine around it and add a label so I can move it to a better location. I can understand why vendors dig them up and reset them every year. It should help them keep track of what they have as well as helping to propagate them. Too much work for me though.
I do know how much time it takes to take pictures and post them, and it sure is nice when people are kind enough to make a comment or two. Even nicer if they take the time to give a thumb to a picture that you put in the database.