Hello; I'am also in zone
6 in Michigan,just north of Detroit and
I've always dug mine up in the fall and harvest the corns,I think
that is what they are call, anyway, and plant them in a pot in my
basement over winter,then plant them outside in early spring
I clean the bulbs and soak them in a solution of 10-1 water and bleach
to kill any desease or bugs, then let them dry in a box,uncovered.
I store them in the basement on the floor,in the box. the cold floor
will cause them to go dorment.
I'am "glad" you like glads....