Cannas do v. well in containers. I always keep a few leftovers and grow them indoors as houseplants in 8 inch pots over the winter. They often bloom (not yet this year....)

But..., I stick to smaller varieties. My largest outside containers are whiskey barrels, and I typically use 3 foot cannas in those. As an example, "Tropical Sunrise" (3 ft) is a variety I might consider for this use. Once they're in a tall container, they seem tall. Horn Canna Farm has a nice selection w/photos online.

Here is a link that might be useful: Horn Canna Farm

Hi Stan,I use cannas in my container planting a lot. I use a canna as the "something tall " background plant & have fillers & spillers.I use Tropicanna & Bengal Tiger a lot in my mixed container plantings.You don't want to use a large bulb.3 shoots are about right for a mixed pot. A whiskey barrel would accomodate a large planting. They like lots of water! I've had them break a pot because they got too large. Sometimes what you plant doesn't seem too big,but there can be dormant eyes that will send up new shoots.

I used to have a shorter,dark leaf one with kind of a salmon red flower.I bought it as Wyoming,but I'm not sure it was. I saw it at your garden & you didn't call it Wyoming.I liked it because it bloomed so readily.

I just love growing in containers,maybe because planting at ground level becomes harder every year LOL
But,you do have to be home to water them.
Doris