Hibiscus syriacus, or Rose of Sharon, is a deciduous shrub that grows to about ten feet tall and six feet wide. It sports very showy, two to three inch flowers from summer until frost. It is easy to grow, actually likes heat and can tolerate some drought. Flower colors include white, pink, red and shades of purple.
Hibiscus moscheutos is a perennial form that dies to the ground in winter. Bloom starts in late spring or early summer and continues until frost. The flowers can be white, pink or red and are very large, reaching almost a foot wide. The plant grows to six to eight feet high and three feet wide. This one needs regular water.