Question
Our back 8' fence is a solid cover of the neighbor's star jasmine that has been growing for many, many years.  They routinely trim the vine creating fence carpet for their pool area.  I simply twist the advancing vine ends back into the massive cover. We live in Zone 9 so the vine often blooms multiple times throughout the year.  The blooms are sparce and may be affected by the trimming on the other side.  

We are often out evenings and would enjoy a showier fence covering.  Could I plant moonflower vine using the star jasmine as the trellis?  As the vine is an annual, I would think it not invasive enough to damage the very mature, massive stand of star jasmine.  Then I wondered if it would flower should it embed to deeply into the star jasmine.  

Your thoughts would be much appreciated.  It is spring in our neck of the woods and I am already sowing flowering annual directly into the beds.  

Thank you for your time in this.  
Debbie Storey

Answer
Hello Debbie -
The Star Jasmine fence sounds gorgeous ... and I am somewhat amazed that it hasn't brought the fence down by now, although it could be what's holding the fence UP at this point, depending on the strength of the fence's original construction!  Anyway, yes, the moonflower would certainly find that the Star Jasmine would be a fine "trellis," as long as you trim the moonflower back after each flush of blooms to encourage lateral growth.  In fact, I think it will look pretty spectacular! It will not embed itself so deeply that it does not flower...most flowering vines are uncannily "smart" enough to know just where to go to maximize their blooming.  As far as the scarcity of blooms go (regarding the star jasmine), that could be due to 3 things: (1) not enough pollinators around (doubtful, since you are in Zone 9, unless your local insect populations have taken an unnatural hit in the last few years); (2) soil/nutrient fatigue -- it could be that the star jasmine, being so mature, has simply sucked the life out of the soil and a little human intervention (i.e. fertilizer) is required; or (3) your neighbors are pruning their star jasmine at some inopportune times and places (i.e., not soon enough after it blooms, so they are actually cutting back buds).  Flowering vines need pruning only back to the 5th or 6th budding "node" and if they are trimmed too vigorously, they won't put on much of a show for a while.
I hope this hasn't been too rambling; please let me know how things go with the moonflower/star jasmine combo or even send a photo or two - it all sounds perfectly plausible, not to mention intriguing...and thanks for posting your question!