No Hibiscus are not all hybrid. Most Hibiscus commonly seen for sale are hybrid like rosa-sinensis, a lot of H. moscheutos (like those in your photo) and H. syriacus, but there are hundreds of species of Hibiscus that are not hybrids. All but three of those listed in my first post are natural straight species and the three that are hybrid do come true from seeds. Also some H. moscheutos such as the Luna series and Disco Belle series come true from seed. Some are annuals and some are perennials that can be grown as annuals but any perennials that can't survive winter temperatures will be brought inside on cold days. We have very few freezing days here so protecting tender perennial is not a big problem.