Q.mock orange
It needs pruning. Can I do it now? Also, some leaves have white on them.
Certified GKH Gardening Expert
Mock orange should be pruned just after it has flowered and the flowers have faded. You can prune now without hurting the plant, but you won't see flowers next year.
Mock orange is susceptible to powdery mildew, a fungal disease that produces a white "powder" on the leaves.
http://www.extension.umn.edu/garden/diagnose/plant/deciduous/mockorange/spotsorblotches.html
https://www.gardeningknowhow.com/plant-problems/disease/powdery-mildew-homemade-and-organic-remedies.htm