You can begin new rose of Sharon plants without having to buy them if you already own one. You can take cuttings in the fall after the leaves have dropped, and propagate them. With a few cuts and some careful planting, you'll find propagating rose of Sharon fairly easy and rewarding. All you need is a protected place to grow them for a year or two, and a location where you want your plants to live permanently.
Clip strong, pencil-thick stems off the parent plant near the base of where they separate from the main trunk. Trim each cutting down to around 10 inches long with end cuts falling just before and after a bud.
Form a narrow trench in an area of your yard that is protected from wind but receives full sun. Make the trench approximately 6 to 8 inches deep. Fill the bottom of the trench with an inch or two of sand.
Anchor the cuttings vertically, spaced 3 to 4 inches apart, with the base pushed into the sand. Fill the trench, covering half to two-thirds of the cutting.
Moisten the soil thoroughly, but don't oversaturate it. Keep supplying water to your cuttings for the first month to keep the soil damp.
Continue to water and weed the cuttings as needed over the winter and first growing season. Transplant strong cuttings in their second spring to a permanent site, but leave weak ones until the next spring.