The mock orange, Philadelphus virginalis, is a popular shrub that has orange-scented white flowers in late spring until early summer. Like other shrubs, it benefits from pruning shortly after it finishes blooming. Many species of mock orange exist---some grow to only 3 or 4 feet tall while one native species can reach 20 feet. Several pruning methods are used for shrubs, including the mock orange. You'll need to evaluate the condition and appearance of your shrub to determine which method is appropriate for it.
Allow new plants to grow without pruning until they are at least 2 years old. After they bloom, prune off all older wood that has produced flowers.
Pinch off young shoots at any time of year to encourage any shrub to develop a bushy, compact form. This practice eliminates the need for you to do further pruning later in the year.
Prune to thin out branches of your shrub. Cut the plant's oldest, tallest branches to the main stem first and then cut other branches to create the shape you want.
Cut woody branches back to a bud or another branch to force shoots to grow below your cut area. This practice is called heading back and it helps to make your shrub more dense.
Prune the oldest, most woody branches all the way back to the soil line to renew your shrub. Also cut all small stems to the ground, leaving only the healthiest looking medium-sized branches. Mock orange benefits from severe renewal pruning, in which you cut all branches to the ground.