I've done it before and they looked absolutely fabulous in planters. I used a very large planter and if it's your wish to have a large tall & lush planting, I would suggest the same thing. I didn't do anything special to keep the water moist, but in summer I did water almost daily. If dryness is your concern, don't use completely soiless mixes which require frequent watering. Use moisture retentive gel crystals... There are drip irrigation systems that you can easily set up which are useful too. I tried them once on timer when I had to travel. I returned and boy my yard looked so lush.. I highly recommend it.

As for plant food, I hardly used any - except composted manure.

As a child in Asia, this plant grew wild in our canals. So I can surmise that all these plants need is organic fertilizers and kept moist.

That is good to know ianna, thanks for replying. I planted up a lot yesterday so I'll see what happens.

Cannas like wet feet and will grow with pots in a pond, so they may do well in a pot without drainage, like a mini pond.