Cannas and callas in a pond

I have been told that cannas and callas are OK for a pond. does it depend on the cultivar? Is this info even true?

 

Out of sheer laziness, I have had five cannas growing( now blooming) in a three gallon plastic bucket of water, patiently awaiting for me to find time to pot them in soil. They have been patient for 3 1/2 months, and I'm embarrassed admitting it. Callas might well be as patient.

 

Thanks for the info... I may give er' a go.

 

An additional thought: I have potted cannas in a soil/sand mix(the sand for weight) and set the pot in my pond. WIth the top of the pot (soil) an inch above the water, they grew for a year, 'til I got tired of them and went to different plants.