I just bought blue and white hydrangeas this year and planted them in containers on my terrace; in hindsight, it may not have been a great idea because they are on my terrace with very little shade, and oh yeah, did I mention I live in Italy, so it gets pretty hot. Heat is not exactly what hydrangeas prefer, but hey, their still alive and will probably have to create shade for them when it gets hotter. They look beautiful, but the blue one is doing better than the white one. I'm not much help and I think you've made a great choice because they are beautiful