It's been a rough winter here in central SC (many lows in the teens with ice and heavy frost), but I've rooted several varieties of very cold hardy oleander whose leaves are still green. I think they'd be root hardy to at least zone 7a. I've yet to find a ice pink or salmon color (my favorite) that can survive in my zone. Anyway, I want to move my cold hardy oleanders, but I don't know the best time. Please advise.