Star Flower (Pentas lanceolata) are Hummingbird and Butterfly magnets! I grow both the standard size and dwarf types which are perennial's here in Florida if we don't get consecutive freezes, but they'd definitely be annuals in your zone ... still well worth using as filler plants in the summer garden!
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!