Mock orange plants (Philadelphus coronarius) are deciduous, flowering shrubs. Desirable for their fragrant, creamy-white flowers that mimic those of orange trees, these shrubs are a good choice for home gardeners who want a hardy, spring-blooming shrub. Mock orange shrubs can grow to an average height of 10 feet, according to the University of Illinois, and have a rounded, arching shape. They grow best in United States Department of Agriculture (UDSA) plant hardiness zones 4 through 8.
Expose your mock orange shrub to plenty of sunlight. It's the blooms that make this plant special. Without at least six hours of sun exposure per day, the plant will not bloom well, according to the University of Connecticut.
Add rich, organic material to the soil around your mock orange shrub. A thick layer (3 to 4 inches) of mulch consisting of leaf mold or compost will add nutrients to the soil and keep it moist. Extend the mulch to the edges of the shrub's canopy.
Water enough so that the soil is continually moist, but never soggy. Too much water in the soil can lead to root rot, which is a fungal disease that destroys the roots of the plant. Although they are tolerant of drought conditions, mock oranges grow best in moist, well-draining soil, according to the University of North Carolina.
Fertilize sparingly. The roots of these plants are sensitive to fertilizer burn. A mulch will add plenty of nutrients. Only fertilize in early spring if the plant has yellow leaves, which is a symptom of nutrient deficiency. Use a balanced (10-10-10) fertilizer and follow the directions on the label for application according to the size of your mock orange shrub.
Prune every year after the shrub flowers. Mock oranges can get "leggy" with age, which means they spread out in a rather loose, messy shape. Prune the shrub back by a third early each summer, after the flowers have faded.