They can grown anywhere from 5-15 feet. It depends on how close together you plant them and how much water they get. The tallest one I have is 14ft (and growing!) and some of the smaller ones (because I planted wayyyyy too many in a small area) are 5-7 ft. I live in Texas and yes, I constantly keep planting them, would imagine they would do well anywhere warm with sun :)
Also, these are an ESSENTIAL for any veggie/herb gardener. Bugs (stink bugs, aphids, etc) love these over other plants so I always plant them in between to distract bugs from the others. These guys are tough enough to take it, too!