I am not currently growing any varieties of the most well-known species of Hibiscus, Hibiscus rosa-sinensis, nor of the rose of Sharon (Hibiscus syriacus). However, despite not having either of these common ornamental shrubs at the moment, there are three different types of Hibiscus blooming in the garden right now: the annual flower-of-an-hour or bladder hibiscus (Hibiscus trionum) and roselle (Hibiscus sabdariffa) and the herbaceous perennial swamp rose mallow (Hibiscus moscheutos).
Flower-of-an-hour (Hibiscus trionum)
Roselle (Hibiscus sabdariffa)
Swamp rose mallow (Hibiscus moscheutos)
I also have some specimens of Hibiscus acetosella which are now beginning to bud, though with temperatures cooling down I am not sure they will make it to flower.