The best way to propagate these is by softwood cuttings in early summer or semi-ripe cuttings in summer and autumn. Take a soft shoot about 4 or 5 inches long, trim off just below a leaf joint and take off any lower leaves. Put it into a free draining compost around the edge of a pot. Take a few as they may not all root. Water the pot and put it in a propagator or in a plastic bag with the top tied. Leave in a sheltered spot until rooted. Then pot on separately and grow on for a year.