I'm aware that Canna virus is a big problem, and certainly that was the case for me last year. Out of 6 shop-bought rhizomes, 5 of them were riddled with virus. I grew a healthy Canna 'Picasso' that I overwintered as a houseplant (just to have a tropical foliage effect in the house - I overwintered most of my Cannas as dry rhizomes); it's growing new leaves but they are quite spindly and have brownish streaks; does that sound like virus, or could it just be caused by keeping the plant in a too-dry indoor environment?

Thanks for any advice.