It's definitely a canna and you're right--they're not hardy to Z5b. However, it's planted up against your foundation where it gets some heat it wouldn't get if it were planted farther away from the concrete. In addition, it may be planted just deep enough to escape the frozen ground. Those flowers are a lovely shade of red.

Thanks,

I guess that I am so lucky to have an annual return year after year. Should I mulch that area heavily to help the plant survive another couple of years?

Paul

Cannas are actually perennial tubers. If it has established there, it should be fine how it's been the past few years. Unless you have disturbed the soil level or significantly increased or decreased the amount of shade/sun exposure there.

When I was a kid, in south TX, that canna was referred to a Panamanian.
If I remember correctly it sets seed.

Kathy