Now is the time to do it as the temperatures are nice and warm. Take cuttings of the growth that is semi-ripe. Not the newest, not the oldest. About 8" Leave two leaf sets on the top, dip the base in a rooting hormone powder. Fill a one gallon pot with soiless mix, or 50 topsoil, 30 sphagnum peat moss 20 sand, use a pencil to poke a hole about 4" down. Plant 3-5 clippings per gallon and place in a fairly bright but shady place. Not in direct sun. Keep the cuttings moist, but don't drown them. They should root in a month or two and be ready to plant out in the fall. They will probably loose their cutting leaves, but will then sprout new leaves. This is a good sign that they are taking root. If all 5 root, you may want to gently take them out and repot them seperately until the fall. If you plan to plant them in a place where you can't get water to them the first year after planting, then you should probably just keep them potted, one to a gallon, until the next spring and them plant them out. They are very tough plants and should do nicely.