I grow mine in the ground down here. It returns from the roots (just starting now) and grows to a height and width of about three feet. It is in a bed that gets mostly dappled sunlight. During the two hours or so that it gets direct sun it tends to wilt. It likes moist roots.

I have seen a specimen at the New Orleans Botanical Garden get to about five feet tall and bloom. It must have special protection because mine has never bloomed and will freeze to the ground when the temperatures get below 40 degrees.