Certain plants, such as spider plants, send off long slender stems called runners. New plants, or plantlets, that can be used for propagationRead how to propagate houseplants by Plant Division at HousePlant411.com, often develop at the ends of these runners. Place the plantlets on top of potting soil while they are still attached to the original plant. The plantlets will continue to get nutrition from the parent plant while developing roots of its own. Pin the plantlet to the soil with an open paper clip or a small piece of wire. Once the plantlet has rooted, sever the connection to the parent plant. Alternately, some plantlets can be carefully removed from the runners of the original plant and directly potted.