Tree cosies

Spotted on the way home from the art gallery today: a forest of rainbow trees!
I've seen a lot of tree cosies around in Wellington and elsewhere, but this crop is especially well done. Obviously a lot of skill and effort went into them, and I love that they're all different...

 According to the little tags pinned to the cosies, they're the work of an international yarn-bombing group called Yarn Corner. Naturally, I looked them up when I got home and joined. Time to dust off my crochet hook!