We just started growing Canna’s a couple years ago, and have found they make excellent plants for several large pots that are used to ‘soften’ this property line fence.
A local nursery gave me the large black plastic pots for free, and they should work well for many growing seasons. They were filled this spring with BX Mix (after risk of frost) and planted with one Canna and one Geranium each. They receive a monthly fertilization with Osmocote, which I find much easier to use than more frequent applications of liquid fertilizer.
Yesterday, I posted this short video on how to maintain Cannas, showing removal of the spent flower stalks, along with basic grooming.
You might want to give them a try in flower pots or your garden, there are some amazing color combinations available, far beyond the standard red ones!