If you are referring to the Giant or White Bird of Paradise (Strelitzia nicolae), it is rated as winter hardy in zones 9+. Although they can briefly tolerate temps in the 20's, a zone 7B gets too cold in an average winter for them. They will not survive in the ground in a zone 7B. Grow them in a container and place them outside in the growing season (mine are outside from about mid April until early-late November (depending). Protect from frost when you bring them inside. I actually have overwintered mine in a bright, frostfree (attached) garage. They do very well in containers!