The only jasmine I've successfully rooted, I rooted in florists' foam. I get the foam at Wal-Mart---it's comething called 'wet' foam. Soak it in water for several minutes, then cut it into small cubes. Dip the ends of your cuttings in rooting hormone, then insert them about half-way into the foam. Place the foan into a tray, and keep it wet at ALL times---once it dries out, it resists getting wet again.

I took cuttings from my mom's star jasmine last fall---October, maybe?---and just TODAY moved them into pots with dirt. TAkes a LOOOOONG time, but 95% of them eventually rooted!