Cut the immature stems about three to five inches, just below a node, in mid summer, dip in root powder before planting. This powder can be found at a nursery. Water with a fine spray, they do not need a lot of water.
American bittersweet is propagated by softwood cuttings. Take cuttings of new growth in early summer, dip them in rooting hormone, and place in a sterile potting mix. Place a clear plastic bag over the pot to keep the humidity around the plant high, and keep the soil moist. Plant the rooted cutting in early fall.