Still maturing in my gardens, I'm mostly relying on information from the internet about this species. They are generally described as growing along the edges of forests or woodlands, or in clearings, being very tolerant of low nutrient soils and growing into a distinctly narrow, upright form anywhere from 3' to 5' in height. From what I can see in photos they seem to be semi-clump forming, rather than strongly spreading. An interesting species to try in a dappled shade setting for some late summer colour, height and pollinator food.
Illustration: Mary Emily Eaton, New York Botanical Garden Photo from Laval University,