Those fiery red blooms look pretty ragged in late fall so this is a fine time to think about keeping them for the winter. There are three methods: keep them potted indoors in a sunny window, store them “roots, soil and all” in a paper bag in the basement or start new plants from cuttings.
October is the perfect time to start cuttings. Just use sharp scissors to cut a 5″ section of stem, just below a joint. Remove all but the top leaves and stick the cutting in a 4″ plastic pot full of potting soil. Put your pots and cuttings in a sunny window and keep the soil moist (but not soggy) for a week.
For the rest of the winter, care for them as you would any houseplant. You’ll have plenty of small geraniums to put outside when warm weather comes next spring.