Publication #ENH999

Topics: Environmental Horticulture� |� North Florida REC-Quincy� |�Hibiscus� |� Knox, Gary W� |�Schoellhorn, Richard Kent�

Hardy Hibiscus for Florida Landscapes¹

Gary W. Knox and Rick Schoellhorn²

Hardy hibiscus are an overlooked group of perennials with tremendous potential for the landscape. Hardy hibiscus are herbaceous perennial members of the genus, Hibiscus. They are large-flowered, fast-growing plants up to 15 feet tall and 4 to 8 feet wide. They are close relatives of the tropical hibiscus (Hibiscus rosa-sinensis) seen commonly in the landscapes of southern and central Florida. Unlike their tropical counterparts, however, hardy hibiscus are much more cold hardy, vigorous, and long lasting, and they have larger flowers.

In north and central Florida, these plants emerge from the ground in mid to late spring and bloom from late spring through fall. With the exception of some of the herbaceous species, a hard freeze kills the above-ground growth but below-ground stems over winter and produce new shoots the following spring. Some species require freezing (chilling hours) to release vigorous new growth making them better suited for north and central Florida than for south Florida. Hardy hibiscus prefer full sun or partial shade and any soil that is not too dry. Hardy hibiscus are especially useful in areas where the soil is too wet for other perennials. In the landscape, they are often used as colorful, flowering specimen plants, as borders or as taller components of perennial gardens. Many are well suited to semi-aquatic conditions and can be a great way to plant marshy areas that are otherwise maintenance problems. Some, such as swamp rosemallow (H. grandiflorus), are salt tolerant and are very adaptable to coastal areas. Hardy hibiscus is the perfect centerpiece plant in large mixed containers or planted alone. The bigger the container the bigger the impact it makes.

Hardy Hibiscus Species

Many Hardy Hibiscus are native to Florida and the southeastern United States, including comfortroot (Hibiscus aculeatus), scarlet rosemallow (H. coccineus), swamp rosemallow (H. grandiflorus), halberdleaf rosemallow (H. laevis) and crimsoneyed rosemallow (H. moscheutos). These species are worthy of landscape use in their own right. Swamp rosemallow has rich fuzzy gray green leaves on a plant that reaches up to 15 feet in height. This species is salt tolerant and can grow in brackish water directly in the tidal zones. Flowers of H. grandiflorus are about 8 to 10 inches across and a clear soft pink. Flowers of scarlet rosemallow are most commonly a clear red with petals that don't overlap, but the range of forms and closely related species will vary a lot.

Confederate Rose, Hibiscus mutabilis, is an old fashioned garden plant of the southern U.S. This upright, tree-like species grows up to 15 feet high and 10 feet wide in freeze-free areas of south and central Florida. In north Florida, heights of 6 to 8 feet are more common due to the annual hard freezes. Large-leaved and coarse-textured, confederate rose begins flowering in late summer producing 6- to 8-inch blooms that open white and fade to pink. One of its most notable features is that white, light pink and dark pink flowers can be found at the same time on any given plant. The most common form is 'Flora Plena' with double flowers, but a single-flowered form also can be found. Another cultivar of this species, H. mutabilis, Rubra, is a smaller statured plant (usually 4 to 6 feet in height) with single intense deep pink to carmine blooms.

Other Hardy Hibiscus species are grown for food or fiber as well as ornament. African Rosemallow (Hibiscus acetosella) has become popular as a foliage color annual in plantings around the U.S. Kenaf (H. cannabinus) is grown for its stem fibers that are used for making textiles or paper. A variety of kenaf formerly known as H. sabdariffa is a food plant with the common names of “Roselle,” “Jamaica Sorrel” and “Florida Cranberry.” The main edible part is the fleshy sepal, called a calyx, that surrounds the fading flower and developing seed capsule. The ornamental calyx is bright red and acid and is used to make tea, juice, jelly or a cranberry-like sauce.

Commercial Hybrids

Crimsoneyed rosemallow (Hibiscus moscheutos) and several other species have been used extensively in breeding programs. These hybrids produce spectacular flowers up to 12 inches across in shades of white, pink and red. Recent breeding programs are supplanting older cultivars such as 'Disco Belle Mix' and 'Southern Belle' with more vigorous cultivars such as 'Fireball'^{PP 13,631} and 'Super Rose'. These newer cultivars tend to grow smaller and more compact than the species. The 'Luna' series is exceptionally dwarf and available as a seed produced crop, while others like the 'Vintage' series are produced only by cuttings and offer new tones of deep cerise on dwarf plants. Some cultivars, such as 'Red Shield' and 'Kopper King'^{PP 10,793}, have been selected for their burgundy to purple foliage.

Characteristics of Hardy Hibiscus

Characteristics of selected hardy hibiscus under evaluation in north Florida are listed in Tables 1 and 2. Other commercial cultivars include 'Anne Arundel', 'Cerise', 'Cranberry Punch'™, 'Crimson Wonder', 'Crown Jewels'^{PP 11,857}, 'Davis Creek', 'Flare', 'Giant Maroon', 'Pink Clouds', 'Plum Crazy'^{PP 11,854}, 'Raspberry Rose', 'Red Flyer', 'Robert Fleming'^PPAF, 'Royal Gems' and 'Sweet Caroline'.

Care of Hardy Hibiscus in the Garden

The major insect pest of hardy hibiscus is the caterpillar-like larva of the hibiscus sawfly, (Atomacera decepta). Several of these larvae often feed on the same leaf or plant and can quickly defoliate the entire plant. Other pests include whiteflies, mealy bugs, grasshoppers and spider mites. The primary diseases are various leaf spots caused by Cladosporium, Cercospora, Phyllosticta and other fungi.

Figure 1.

Comfortroot, Hibiscus aculeatus

Figure 2.

Hibiscus Blue River II

Figure 3.

Hibiscus cannabinus

Figure 4.

Scarlet rosemallow, Hibiscus coccineus

Figure 5.

Neches River rosemallow, Hibiscus dasycalyx

Figure 6.

Hibiscus Disco Belle

Figure 7.

Hibiscus Fantasia

Figure 8.

Hibiscus Fireball

Figure 9.

Swamp rosemallow, Hibiscus grandiflorus

Figure 10.

Hibiscus Lady Baltimore

Figure 11.

Halberdleaf rosemallow, Hibiscus laevis

Figure 12.

Hibiscus Lord Baltimore

Figure 13.

Hibiscus mutabilis Rubra

Figure 14.

Hibiscus Super Rose

Figure 15.

Hibiscus Turn of the Century

Figure 16.

Crimsoneyed rosemallow, Hibiscus moscheutos

Tables

Table 1.

Characteristics of native or species forms of hardy hibiscus under evaluation at University of Florida/IFAS facilities.

Species/Cultivar	Common Name	Flower Color	Habit	Trialing Location
H. acetosella	African rosemallow	Yellow	Upright	Quincy, FL
H. aculeatus	Comfortroot	Yellow	Spreading	Quincy, FL
H. cannabinus	Kenaf, roselle, Jamaica sorrel, Florida cranberry	Yellow	Mounding	Quincy, FL
H. coccineus	Scarlet rosemallow	Red	Very Upright	Gainesville, FL Quincy, FL
H. dasycalyx	Neches River rosemallow	White	Mounding	Quincy, FL
H. grandiflorus	Swamp rosemallow	Light pink with red eye	Very Upright	Gainesville, FL Quincy, FL
H. laevis	Halberdleaf rosemallow	Pink with red eye	Upright	Quincy, FL
H. moscheutos	Crimsoneyed rosemallow	White or pink with red eye	Upright	Quincy, FL
H. mutabilis Flora Plena	Flora Plena Confederate rose, Flora Plena Dixie rosemallow	White, fading to pink	Very Upright	Gainesville, FL
H. mutabilis Rubra	Rubra Confederate rose, Rubra Dixie rosemallow	Deep pink - cerise	Upright	Gainesville, FL

Table 2.

Characteristics of hardy hibiscus hybrids under evaluation at University of Florida/IFAS facilities.

Cultivar/Species	Flower Color	Habit	Trialing Location
Blue River II	White	Mounding	Quincy, FL
Disco Belle Series	Red, blush, pink, white	Upright	Gainesville, FL
Fantasia^{PP 11,853}	Ruffled pink	Mounding	Quincy, FL
Fireball^{PP 13,631}	Deep red	Upright	Quincy, FL
Kopper King^{PP 10,793}	Pale pink	Upright	Gainesville, FL
Lord Baltimore	Red	Upright	Gainesville, FL
Lady Baltimore	Pink	Mounding	Gainesville, FL
Luna Series^PPAF	Red, blush	Compact	Gainesville, FL
Moy Grande	Pink	Upright	Gainesville, FL
Old Yella^PPAF	Cream with a red center	Upright	Gainesville, FL
Red Shield	Yellow	Upright	Quincy, FL
Rio Grande	Solid red	Upright	Gainesville, FL
Southern Belle	Red, blush, white, pink	Upright	Quincy, FL
Super Rose	Rose pink	Mounding	Quincy, FL
Turn of the Century	Pink/white bicolor	Upright	Quincy, FL
Vintage ^PPAF	Red, white, pink, blush.	Compact	Gainesville, FL

Footnotes

This document is ENH999, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date, October 2005. Reviewed October 2008. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.

Gary W. Knox, Extension Specialist and Professor, Environmental Horticulture Department, North Florida Research and Education Center, 155 Research Road, Quincy, FL 32351, and Rick Schoellhorn, former Floriculture Extension Specialist and Associate Professor, Environmental Horticulture Department, 2523 Fifield Hall, University of Florida/IFAS, Gainesville, FL, 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.

Hardy Hibiscus for Florida Landscapes1