When is the best time of the year to dig up and move cannas? Mine winter well here, but they just need dividing.
The best time is late winter or spring. I've done it in the middle of summer also, which caused some temporary wilting and a slight setback in the season's growth.
You can move them anytime if you're careful, but to me, late summer or fall would seem like the worst time to divide cannas. The rhizomes would not have time to recover before going dormant.