Yes, after it stops blooming is a good time to prune. And yes, it's going to be big job. It has terrible white drippy sap that may be irritating. It doesn't give me a rash but it sure does stain. I would suggest hiring someone to trim it if you think it's going to be too big of a job. Or else just plan on working on it a little bit at a time and just whittling away at it gradually. Good luck.

And speaking of jasmines,
I've cut nite blooming to nubs and it comes back. Stuck pieces in pots and it roots. Pulled a star jasmine out of it's pot. Cut off the tap root that was stuck in the drainage hole, hacked it and left it for dead. NOT!
So I put it in another pot. This stuff is hard to kill, but like jen said, be careful of the sap.
Isn't the fragrance heavenly?

Yes. I love the aroma. Im familiar with the sap as I have pruned it slightly before. Just wasn't sure how hard I could prune it and if pruning it late in the year would prevent it from blooming. My night blooming jasmine looks leggy and sad. It's quite large, but years ago when I cut one back severly it never made it. But I am going to try cutting it back gradually and hope for the best. Thenks for the information.

Pat

We inherited a giant confederate jasmine with our house and the first year I timidly cut it with pruners.... the next year I went at it with an electric hedge trimmer, which I highly recommend, it makes it a much, much easier and faster job than trying to hand prune, it was a 15 min job compared to a 40 minute job the first time.

I have approx. 1000 sq. ft. of confederate jasmine as ground cover under an oak tree. How can I prune it--with a lawn mower with new sharp blades?