1. Take cuttings from a healthy, vigorous parent plant. Look for wood from the previous season’s growth, which is often lighter in color than older wood. With a sharp knife, cut pencil-thick stems 1 to 2 feet long.
To prepare the cuttings, slice off and discard the top inch or two of each stem (this is unripened wood and does not contain enough nutrients to survive). Then cut the stems into 6- to 9-inch lengths, each with two or three nodes. Make the cuts about 1/2 inch above or below a node; to help you remember which end of each cutting is the top, make the top cuts at a slant. Dip the bottom ends in rooting hormone powder and tap off the excess.
2. If you live in a climate where the ground freezes, store the cuttings, bundled together and fastened with rubber bands, in a box filled with slightly moist vermiculite, sawdust, or sand (cover the cuttings completely). Place the box in an unheated (but not freezing) garage or shed. In warmer areas, you can bury the bundles in an outdoor trench filled with regular garden soil. During winter, the lower ends of the cuttings will begin to form calluses from which the roots will grow.
3. In early spring, plant the cuttings in a nursery area protected from strong winds. Dig a narrow trench and set in the cuttings, top end up and about 6 inches apart. Fill in the trench with soil mixed with compost or perlite, leaving only the top bud of each cutting exposed. Firm soil around the cuttings.
4. During the growing season, water as needed to keep soil moist; protect cuttings from direct sun with shade cloth or a lattice supported on stakes. By fall or the next spring, the new plants should be ready for the garden.