Hardy Hibiscus Plants

Some hardy hibiscus produce huge flowers.

While hibiscus is generally thought of as a tropical plant, a certain species of hibiscus, scientific name Hibiscus moscheutos, actually grows in areas where temperatures drop below freezing. Called hardy hibiscus, and also known as the rose mallow or swamp mallow, these perennial shrubs are prized for their attractive foliage and large, colorful and showy flowers. Frequently used as specimen plants, hardy hibiscus grow well when planted either within the landscape or as container plants.

Description

The leaves of hardy hibiscus are medium green, dull in appearance, rounded and grow alternately along tall, thin, woody stems that typically reach from 3 to 8 feet tall. The flowers come in a wide variety of shapes and colors, ranging from white to pinks, reds, scarlet and plum. Some varieties produce variegated flowers with multiple colors. Many varieties grow extremely large blossoms that can reach up to 12 inches in diameter.

Range

Hardy hibiscus grow in a much wider area than tropical hibiscus, which typically die completely from cold exposure in areas that experience freezing temperatures. The range of hardy hibiscus extends north, well into USDA hardiness zone 4 and marginally into some southern areas of zone 3, and as far south as zone 9.

Growth Habits

Hardy hibiscus grows relatively quickly. Sprouting later than many other perennials, hardy hibiscus will often begin to show in late spring and may not produce blooms until mid- to late summer. In areas where freezing temperatures occur, the plant will often die back to the ground, then produce new growth the following spring.

Culture

Hardy hibiscus species typically prefer moist, fertile, acid soils and will often thrive in wet soils where other perennials may not grow. Some hardy hibiscus varieties, such as swamp mallow, are capable of growing in semiaquatic environments. These plants prefer full sun, but can tolerate partial shade. Within the landscape, hardy hibiscus are well suited for growing in containers, as long as the soil does not dry out. Some species, including swamp rose mallow, are salt tolerant and grow well in coastal areas.

References

• University of Florida IFAS Extension; Hardy Hibiscus for Florida Landscapes; Gary W. Knox et al.; 2008
• U.S. Department of Agriculture: Hibiscus moscheutos L.
• Bachman's: Hardy Hibiscus
• Kemper Center for Home Gardening: Hibiscus Moscheutos
• Iowa State University Extension; Hardy Hibiscus for a Tropical Look; Linda Naeve; 2002