1) If you dont want seeds the yes, most canna hybrids do not produce fertile seeds any how and that is spent energy.

2)Pots or bed is fine. Mine tend to do better in thd bed, but you will need to winterize them in you area. Some cannas do fine in set soil some do not, just make sure the water is not stagnant.

3) I would put them in full sun there, they at least 5-6 hours of light to perform at their best IMO.
4)I do not have any great secrets for this, I just put down a layer or mulch on mine to keep them from freezing. Do a search on the forum and you will see ways others have done this.

Joe

As far as your zone goes, I think you can't really overwinter them outside in zone 5. You will need to dig them up and store them inside a shed or something for the winter. I am in zone 7 and they are supposed to be able to overwinter outside here, but I lost mine last year. Not sure why. We had a mild, dry winter, and I had mulched them well, but I think the moisture in the soil killed them. We have very heavy red clay here. I would put them in one of those plastic storage tubs they sell--fill it with peat, and bury the cannas in it (the tub) and then store it in a shed. Come spring, they'll probably already be sprouting.

I live in zone 5 and I plant my Canna in pots. They do well with regular watering. I overwinter mine by waiting for them to turn yellow, cut them back, dig them up, wash off most of the dirt, let them dry (just from the water, not dry up) and store them in my basement in cardboard boxes. The cooler the better. I have found if I store them in anything even remotely moist they want to grow again and I lose them. I would not recommend them in a shed over the winter as they will freeze. Unless of course the shed is heated. Coolest, darkest place is best to store them. Hope this helps...
Good Luck,
Krafty

Krafty, do you put them in any type of media, or just loose in the box? I thought about just leaving them in the pots to go dormant in the fruit cellar, not a good idea?

crsliz, I think there are as many ways people store their Cannas as there are Cannas. I grow most of mine in pots and I bring the pots and all in to the basement after the frost takes the leaves down. I give the soil a good washing with the hose. The Temp in the basement is between 50 -60 degrees. There is very little light.

I water my pots about a 8 oz glass of water once a month, Just enough so they do not dry out. They start to sprout in March and I usually can put a good size growing plant outside at the end of May.

You have to experiment and see what works for you. I just do not have time to dig up plants so any tender plants I grow are grown in pots and are used on the Patio, and Deck.

Well, if it works for you I would imagine it should for me. I have Brugs, Calla lily, tuberous Begonia, Four o'clocks, and Dahlia to bring in, so I will be busy, also. But, at least they will have good company :)