Red Water Hibiscus (Hibiscus coccineas) is only hardy in Zones 7-11. It has deep crimson flowers that are 5 - 8 inches wide. It is among the reddest of hibiscus in the plant kingdom. Not only are the flowers magnificant but the leaves are narrow and divided, much like that of a Japanese maple leaf. A truly striking plant.
This hibiscus will grow 6 - 9 feet high and 3 - 6 feet wide. Plant it in sun to part shade but it prefers sun. It needs moist soil or water to 4 inches deep. You can winter it over by bringing it indoors or covering it with heavy mulch.
This is another bog plant that is a favorite of the hummingbirds and butterflies.