Some pots have a couple of places along the rim which are doubled - the label fits between and doesn't fall out, and it would take quite a tug for a bird to pull one, though crows are certainly strong enough. I use recycled pots that I pick up at the dump, so I don't know where one can buy them. I've just done a quick check, and these pots are all square, and I have them in blue, green and brown. Diane