They are aggressive about spreading, so you will soon have a forest of clerodendrums if you do not remove volunteers. One of the prettiest plantings I have seen had the Cashmere Bouquet growing with elephant ears. Mynelle Gardens in Jackson has wonderful plantings of this one in addition to the Cleronderum trichotomum, or Glory Bower. Whereas the Cashmere Bouquet develops into a shrub-like habit, the Glory Bower develops into a small tree. Sometimes I have seen more swallowtails than I could count.
Hummingbirds also love to feast on the sweet nectar.
This clerodendrum is special in that after the bloom you have a steel blue fruit in the middle of the red calyx that remains attractive for a long period of time. This native of Japan is hardy in zone 7 as well. Books say they are only hardy in the tropics, yet I have found them growing, blooming and returning in south central Mississippi. I expect we don't know how hardy they really are. Those that appear to be the happiest receive morning sun and afternoon shade.