The best method for overwintering various annuals from the landscape is to take stem cuttings in August.  This way you will be housing smaller, vigorous plants that will successfully survive the winter.  It is possible to dig up plants such as begonia and geranium and place them in large pots in order to overwinter them in the house.  This should also be done in August in order for the plant to adjust to being transplanted.  Plants dug or propagated late in the fall tend to die due to fungal infections that invade the senescent (dying) stems and leaves.

Whether you overwinter rooted cuttings or transplanted plants, be sure to give these annuals maximum light and adequate moisture during the winter months .