Here in NJ we grow baptisia as a hardy perennial. It will reach a small shrub size stature in each growing season, but will completely die back each winter. At maturity it can be 2-3.5' tall and 2-4'wide. The leaves are bluish green, whitish underneath. Early in the summer it will be covered with purple-blue flowers and they give way to jet black seed pods. It's a super cool plant!
I work on a flower farm, we grow them in full sun. In my experience, given full sun and ample water they are going to flower and maintain an upright and rounded form throughout the season. They are truly easy, disease and pest resistant, and stunning!