Blossoms on any plant are not dependant on another plant, just fruiting can be. The usual reason for no blooms is too much nitrogen. Not sure if that applies to mock orange.

tj

My mock orange blooms on new wood. So you need to determine if yours blooms on old or new wood, and prune accordingly.
I have to remember to prune mine right after it blooms in Spring.

Thank you both for replying. I trim it back quite far in the fall, but there should be new and old growth for it to flower on.

It could be your zone. Most Mock Orange are rated for zone 4 or 5. Later spring frosts could be the reason it rarely blooms.

I've done a search on the mock orange and it says they bloom on wood from the previous year. So if you're trimming it back in Fall, you're cutting off the blooms for the next year. They say to trim it right after it's done blooming. But like janetpetiole mentioned, the ones I read about were rated for zones 4 or 5 and the late frosts or very cold winters could be causing too much dieback.

Kat

I agree with Kat. I've got a mock orange that blooms profusely. At one point it was reaching the second story window of our house in height. My husband hacked it off after it bloomed and the next year I had very few blossoms on it. This year was #3 after the trim and it was back to it's abundant blooms.