achang89,
It is a vine. It's really hard to train it as a bush, because it will bloom on the new growth and you won't want to cut it down til you go to bring it in, in the fall.
That is when I really cut it down hard. I literally cut a lot off and put it inside for the winter, but usually have to cut it again in the spring before I bring it outside for the summer.
It's blooming now, and I have it right by my front door so I smell it as soon as I walk outside.
It's potent.
If you look at Home Depot, you might find a really small cute trellis, I think they call it a pot trellis, you can use that to keep it from blowing over in the summer. I got one one year and it wasn't expensive, it's so cute.
It's dark or I would post of pic of mine, unfortunately we have had a lot of rain lately and many of the blooms are brown, but its still pretty.
SO, let it be a vine in the summer when it's outside, and in the fall cut it back hard til you can take it back outside in the summer again, that way you will have more blooms.

hi butterfly,

Could you please post a picture of your Grand Duke Jasmine with trellis. I would like to get an idea.

I have two Grand Duke, one I grow in trellis and other one is new. Not sure whether my DIY trellis is good enough for the Grand Duke

This post was edited by nandakumar on Wed, Jul 17, 13 at 13:57

achang89 hi.
My grand duke is in bush-form, i do not use any trellis or stick cause it just don't need it, and it is doing well. I also have Maid of Orleans, other sambac variety, and that plant is in vine form and needs suport.