Thanks for writing. Be sure your mock orange is growing in a sunny spot (full sun is best) with moist, well-drained soil. Don't prune it; cutting it back at the wrong time of year will stop it from flowering.
Also be sure that your plant is suited to your area; some varieties are hardier than others and if yours isn't reliably hardy, the flowers could be freezing out over the winter.
---Justin, Senior Garden Editor, BHG.com