Tubers

I'm trying to do the right things with my dahlia tubers as this is the first year I've ever grown any.  They've been lifted, dried out a bit, had the soil removed as much as possible and had some of the little roots trimmed.  Now they are in a box and are going in the shed.  Do I need to cover them up?  If so, with what?

Thank you Blippers!  (In anticipation of some helpful suggestions!)