When one searches the topic "serissa from cuttings", they find this string. Whether it's 6 days old or 6 years old, people who are needful of this info might find it useful. Rest assured, the above link is active right now..
I can say with certainty there is a LOT of misinformation in this thread from not only my experience but also very qualified others...
They can take a short freeze down South. Serrisa are NOT tropicals and in fact do poorly up here if treated as such in the Winter...
Another post stated they need Humidity - Bullshit, especially cuttings. They will root, grow, and if exposed to much humidity they will damp off, wither and die. They are very susceptible to fungal problems in high humidity... ALL of them...
They are one of the easiest plants to start from cuttings, even if just dropped on the ground in proper conditions. Here in mid Summer when they are growing and need a LOT of trimming you simply stick them in a pot of whatever crap you have laying around. Put them in the shade and water for two weeks. Two weeks later you will be needing to trim them too. From that point on they can take and should get full sun and stay damp WITH good air circulation. If not they will submit to fungal and die.
They are simple plants to grow and require little care once established except for a lot of trimming. No secret, no mystery.
Grimmy