Hibiscus shrubs always amaze me, somehow. These flowers are inextricably associated in my mind with the warm, breezy tropics. When I think of Hibiscus, I think of the flowers tucked behind an ear in Hawaii, or printed on the shorts of a surfer in Malibu, or cast onto the waters in India. However, there are many varieties of hardy Hibiscus shrub that thrive all the way to Zone 5. We even have a new Hibiscus this year, Hibiscus ‘Jazzberry Jam,’ that is hardy into Zone 4 (and features mammoth 9-inch blooms)!
In the US and Canada, Hibiscus syriacus, the most common hardy Hibiscus, is often referred to as “Rose of Sharon,” though this phrasing has gone somewhat out of style. In the UK and Australia it is the flower Hypericum calycinum that bears that name (in the US that plant is more commonly called Great St. Johns Wort or Aaron’s Beard). Interestingly (to me, anyway), the name Rose of Sharon is a flower mentioned in English translations of the Bible. Nobody is certain what plant exactly it refers to, and Bible scholars have many theories. Neither plant commonly called Rose of Sharon, Hibiscus or Aaron’s Beard, is considered likely to be the real Rose of Sharon, though.
Hibiscus come in a variety of forms, though most of them have the trumpet-shaped flower that one normally associates with them. Some are even showier, though, such as the Hibiscus ‘Boule de Feu,’ an heirloom hibiscus with flowers so showy that they look almost like giant carnations. My favorite Hibiscus, though, is the Rose of Sharon Blue Satin. It’s elegant 3-inch blooms come heavily through much of the summer and even into autumn, and it doesn’t lose any color even in the most brutally hot and sunny spot in my mother’s South Carolina garden.