Unlike any other flower in the garden, hardy hibiscus offer us flowers that are both huge and delicate, as if they were fashioned from crepe paper. The flowers range from a petite 3 or 4 inches across to the proverbial dinner plate, 8 to 12 inches in diameter! In the center of each impressive flower you'll find a prominent pistil and stamen structure that adds to their beauty. For years the only hardy hibiscus colors available were white, pink and red. Thanks to plant collectors and breeders, you can now select some incredible color variations that can be poetically described as hot pink, raspberry, mauve, dusty rose and plum. There is even one interesting new variety called 'Old Yella' with yellow buds that open to a creamy white. The blooms of many varieties have a dark red center and a few have a ruffled edge. Others are bicolored or have attractive dark veins. While each bloom only lasts one day, hardy hibiscus are prolific, sometimes producing more than a hundred blooms in a season. Traditionally, hardy hibiscus were large, rangy plants with large, rounded, medium-green leaves. Plant size now varies greatly, so be sure to take that into consideration when selecting a hardy hibiscus. Many of the new varieties offer smaller, lobed leaves and more compact plant habits. There are even a few with dark, reddish foliage.

Botanically these plants are Hibiscus moscheutos. They are native to marshy areas of North America and sometimes they go by the common name mallow. You may recognize them as close relatives of the not-so-hardy Rose of Sharon shrub, Hibiscus syriacus. They are in the Malvaceae family which also includes hollyhocks and malva. The glossy- leaved tropical flowering hibiscus we love to grow on our patios in the summer is another close relative, Hibiscus rosa-sinensis. Unfortunately for us, that is only winter hardy in climates like Florida. As wonderful as they are, hardy hibiscus have one very frustrating quirk: they tend to be the very last plant to reappear in spring. In fact, many gardeners give up on them and dig them up. But it isn't uncommon at all for hardy hibiscus to wait until late May or early June (when the soil temperature approaches 70º) to make their yearly debut. Looking on the bright side, this late habit makes them great companion plants for spring-blooming bulbs.

The Basics About Hardy Hibiscus

Are hardy hibiscus woody shrubs or perennials? They do have woody stems but they die back to the ground each winter, so they are considered perennials.

How hardy are they? They are reliably hardy in Zone 4 and, with extra protection, marginally hardy in Zone 3.

Do they ever have more than one color bloom on them? Not unless there is more than one plant in the same pot. That happens quite often with seed-grown hibiscus mixes such as Disco Belle and Southern Belle.

When should hibiscus be planted? They can be planted as early as they are available in the growing season (typically in June or July) and as late as Labor Day. When planted any later, they may not survive the first winter.

When will they bloom? Since they get a late start, don't expect to see many blooms before late July or early August.

How long do hibiscus bloom? Once they start blooming, they usually keep blooming until a killing frost in fall.

© Bachman 's 2007