Take 4-inch cuttings using a knife or scissors late in the fall and remove the lower leaves. Throw out the rest of the geranium.
Place the cuttings in a container with damp sand, perlite or vermiculite, about 2 inches deep, until they take root. You can use a rooting hormone by dipping the bottom of the cutting into the hormone powder prior to planting.
Cover with a plastic bag and place in a bright, warm location indoors with indirect sunlight and water every couple of weeks as needed. The plastic bag helps retain moisture.
Check the cuttings for roots by tugging gently and checking for resistance, meaning the cutting has rooted. Plant the cuttings in small containers filled with growing mix when they are at least 1/2 inch in length.
Keep indoors until spring, gradually placing in direct sunlight before planting outdoors in a well-lit, well-drained location.