Hydrangeas respond well to several propagation techniques, including layering and dividing. But rooting softwood cuttings in summer will yield a bunch of new plants in about four weeks. How To : Locate a stem of softwood between the hard, woody growth at the bottom of the plant and the fleshy green tip by bending it; softwood should snap cleanly. Cut a softwood shoot that has several leaves. Trim it into 5-inch-long pieces that each have a leaf toward the top. Remove extra leaves; then cuts…