I have a Philadelphus Starbright in my garden. I have tried to get another one for 3 years, with no luck. I would like to know if I can split it safely.
A Mock Orange cannot be divided but you could propagate by cuttings or even seeds.
Soft wood cuttings can be taken in Summer and hard wood cuttings can be used in Fall or Winter.
Here is a link that explains how to take cuttings.