I hope you disposed of the rhizomes properly. That means not composting as the virus will remain viable in the compost.

Don't give up on canna's. While not bullet proof, they are very easy to grow.

Aquire rhizomes from a trusted source, such as Horn Canna Farm.

Full sun (at least 6 hours direct), lots of water (equivelant to four inches of rain per week), good soil and regular fertilization with a liquid based fertilizer like Miracle Grow or Peters will virtually guarantee vigorous growth with many blooms.

By following the above advice, I went from storing a single milk crate of rhizomes to storing five this winter. I began with ten or so rhizomes two years ago. I'm having to add beds to plant these extras in. They are the Robert Kemp variety. I will also attempt other varieties this spring. Most likely I will have to give away what I haven't room for.