The double mock orange tree is a deciduous shrub that grows to 8 feet tall and is hardy to plant in USDA growing zones 4 and higher. The shrub grows upright and produces white double blooms that have strong fragrance. Propagate double mock orange shrubs by cutting softwood stems from new branch growth in early summer to hardwood stems from current year growth once the plant goes dormant in fall. Softwood stem cuttings propagate roots quickly, making them the preferred option.
Cut 6- to 8-inch softwood or hardwood stems from the mock orange tree with a sharp blade. Softwood mock orange cuttings are branch sections beginning to mature and snap when bent, while hardwood cuttings are mature and in the dormant stage.
Mix a propagation soil for the mock orange cuttings by combining equal amounts of course horticulture sand, peat moss and perlite. Moisten the soil with water and pour it into a propagation tray.
Cut all leaf growth off the bottom half of the softwood mock orange stems with a sharp knife. Dip the lower cut end into rooting hormone to speed the rate of root growth. Stick the mock orange cuttings into the propagation tray and space the stems so the cuttings do not touch each other.
Spray the mock orange cuttings with a water mister to moisten the stems. Cover the propagation tray with a plastic bag and tie it closed with a rubber band or clip. Set the propagation tray in an area that receives indirect sunlight and has a temperature of 68 to 70 degrees F.
Open the plastic covering once or twice a day to mist the mock orange cuttings. Monitor the moisture level in the propagation tray to prevent the soil from becoming saturated. Refrain from misting the stems for several days if the soil becomes wet instead of moist.
Pull on the softwood mock orange stems after three weeks in the propagation environment and hardwood mock orange cuttings after 4 months in the propagation environment. Resistance when pulling on the stems is a sign of root formation. Remove the soil around the stems to monitor the root length.
Transplant mock orange cuttings once the roots reach a length of 1inch or longer. Fill 4-inch growing containers with a dampened, well-draining potting soil and set the stems in at the same depth they were previously growing. Grow the stems indoors through the first winter season and plant outdoors in the spring season.