Do not allow the pots to dry out. When pots are brought inside, acclimate bulbs gradually to inside conditions, keeping them at 50 to 60 degrees for a few days. The average first frost in the Chicago area is Oct. 15. Protect tender plants from light freezes by covering them with sheets, plastic or boxes. When night temperatures begin dropping below 40 degrees, bring in any tropical plants you are keeping outside.
Dahlias are particularly sensitive to frost.
Cut off the main stalk a foot above the ground just before frost. Dig out the tubers, being careful not to cut them, gently knock off the dirt, and let them dry for a few hours. Hardy bulbs deserve more use in Midwest gardens. They add versatility in color, flower form and fragrance. With careful planning, these bulbs will flower from early spring through autumn.