Hibiscus mutabilis 'Plena'

The name requires a brief clarification, and then we can move on to the more interesting parts. Hibiscus mutabilis has been called the Confederate rose since the nineteenth century, when the plant naturalized so thoroughly in the gardens of the American South that people assumed it belonged there. The plant does not. The species belongs to Hunan Province in China, where gardeners have grown the shrub for nearly three thousand years, where the flower serves as the emblem of Chengdu, a city known on its account as the City of Hibiscus, and where classical texts on materia medica describe the flowers and leaves in medicinal detail. The name stuck here out of regional habit rather than botanical or historical accuracy, and the plant is indifferent to the label.

What 'Plena' actually is: a fully double-flowered form of one of the most theatrically interesting shrubs available to Southern gardeners. The flowers of H. mutabilis change color over the course of a single day, driven by a steady accumulation of anthocyanins in the petals. A bloom opens white in the morning, blushes pink by midday, and deepens to rose-red by evening. In the straight species each flower lasts a day before dropping; in 'Plena' the fully double, peony-form flowers hold longer, and the layered petals make the color shift more gradual and more visible. On a mature plant in October you will find all three colors at once on the same shrub, white, pink, and red in various stages of the day's progression. The effect is anything but subtle.

The shrub is fast-growing and substantial. In the Deep South the plant can reach ten feet or more in a single season, carrying large, palmately lobed leaves with a soft, slightly fuzzy texture that lends a lush, almost tropical character. In zone 7 the top dies to the ground in winter and returns vigorously from the roots each spring; in zone 8 and warmer the plant grows effectively woody and persistent. Either way, the space is well earned.

Beyond the spectacle, the plant carries a long ethnobotanical history: in traditional Chinese medicine the leaves and flowers, known as Fu Rong, have been used for centuries in cooling poultices and washes for burns, boils, and skin inflammation. In the garden, give 'Plena' full sun and rich, moist, well-drained soil at the back of a large border or as a specimen with room to spread, and enjoy a shrub that saves the finest show for autumn, when so much else has finished.