2ofus: I am in New England, zone 6a, so a bit warmer than you. I try to start my cannas indoors by April. If I don't, I won't get blossoms until late August. First frost date here is late September, so I try to extend the bloom season by potting up indoors in early spring. Some years I don't get to it & I just plant them outside for their foliage. I keep my cannas in garbage bags & peat moss in a dark basement in winter. It is probably 60 degrees down there & the cannas do just fine. Come April-ish, they start growing all on their own, even in the garbage bags. Some cannas I grow on my terrace in large pots. I just drag the pots to the basement every fall & drag them out again in late May. I don't even change the soil!! I just am sure to fertilize them. I think you can't kill these plants! I love the great big leaves. I have one that has maroon leaves. The foliage itself is a great accent in the garden, with or without flowers.