Locally we call it Malunggay..I grow it from seed in pots and then plant it in ground near an outside sink drain off.. If the roots have good access to water it grows fast...If planted in a dry location it grows very slow..
You can also take a cutting from the main stem and just stick it in the ground and it`ll grow..

In regards growing it in the U.S.. It seems you can!

http://moringafarms.com/growing-moringa/