About a week ago (on November 7) after our first light frost had killed the dahlia leaves, I dug up the tubers, both from the communal flower bed and my own plot including my back porch container dwarf varieties. I roughly cleaned them and let them dry in card board boxes in my back hallway. This morning, I transferred the boxes to a cool dark spot in the basement. I plan to check on them once a month or so and mist them if necessary to prevent them from shriveling up to much. Fingers crossed they will survive.