I'm zone 7 Maryland, and it was an unusually cold winter here. The canna I had planted last year rotted in the ground (I didn't mulch well - was lazy!). I tried to get all the rotted tubers out of the ground, but am not sure I succeeded.

I'd like to plant some canna in the same spot (different cultivar). I know canna are susceptible to certain diseases, but I've only grown them one year, so I'm not too familiar with them. Will the canna I plant this year have disease or nutrition issues since there was rotted canna in the ground?