These are Scheherazade Oriental Trumpet lilies. They've been in the same place for a decade. These bulbs produce flowers that range from 5 feet to 7 feet high.
The group on the left are oversize and in need of division. When they are this big and this close together, they compete for nutrients and are stunted in growth. I will pry apart the three bulbs on the left and re-plant them, giving them more space.
--By Kim Peterson