Hibiscus for Iowa Gardens

There are several Hibiscus species that grow well in Iowa. Growing hibiscus can be confusing to Iowa gardeners because the three most common species vary greatly in flower, habit, and cold hardiness. But all three are worthy of consideration in the outdoor or indoor landscape.

Rose of Sharon
Rose-of-Sharon (Hibiscus syriacus)  Photo by Aaron Steil

The Rose-of-Sharon is a common shrub in home landscapes in the southern half of Iowa. Tropical hibiscus is a common container plant on patios, front steps, and other sunny areas. Hardy Hibiscus or Rose Mallow looks tropical but is winter hardy in Iowa. 


Rose-of-Sharon  |  Tropical Hibiscus  |  Hardy Hibiscus  |  More Information


Rose-of-Sharon

The Rose-of-Sharon or Althea Shrub (Hibiscus syriacus) is a woody shrub.  This is the tallest of the hibiscus species typically grown in Iowa, often reaching 6 or 7 feet. Flowers are 3-4 inches in diameter and are borne by the hundreds starting in mid to late summer. Flowers can be single or double, and are usually pink, red, lavender/blue, or white, sometimes with a contrasting eye or center. Plants thrive in full sun and well-drained soils. Since their cold hardiness is limited to zone 5, there are reliable bloomers in protected locations in central and southern Iowa.

Tropical Hibiscus

tropical hibiscus
Tropical Hibiscus (Hibiscus rosa-sinensis)
Hibiscus rosa-sinensis 'Cooperi'
Vareigated Tropical Hibiscus (Hibiscus rosa-sinensis 'Cooperi') Photo by Aaron Steil

Want something really tropical looking? Look no further than Tropical Hibiscus (Hibiscus rosa-sinensis). This is the species found throughout Hawaii and other warm winter locales. It has brilliant orange, pink, red, yellow, white, and lavender flowers. Flowers can be single or double; have frilled petals, and sometimes contrasting eyes or centers. Both the flowers and the leaves tend to be smaller than those of hardy hibiscus and are always lustrous and richly colored.

Tropical hibiscus is often sold as a patio or container plant in the spring and will not survive an Iowa winter outdoors. Plants are usually brought indoors in September as the temperatures start to drop into the 40's and 50's degrees Fahrenheit. Carefully inspect plants for insects (especially white-fly) before bringing them indoors. Remove any insects that are present with a good wash with an insecticidal soap solution. Plants perform best outdoors in summer in full sun to part shade and require frequent moisture and fertilizer. Once brought indoors, they need bright, direct light to maintain a full complement of leaves. Long days (and short nights) are required to keep plants in flower throughout the winter months.

Hardy Hibiscus

Hardy Hibiscus Red
Hardy Hibiscus 

During the summer months, this hibiscus steals the show.  There are over 35 species of hardy hibiscus, also called rose mallow, native to the US (most in the southeast). Several hybrids have been bred between Hibiscus moscheutos and Hibsicus coccineus, two of the more showy native species.  Hardy Hibiscus species are, as the name implies, cold hardy in the Northern US, including Iowa.  They die back to the ground in fall and re-emerge late the following spring. Flowers are the largest of the hibiscus species grown in Iowa and range from 8 to 12 inches wide when fully open.  Flower colors include red, pink, plum, mauve, white, and lavender often with contrasting or dark eyes in the center of each flower. When in flower, rose mallow will give the landscape a tropical feel without the worry of winterkill.

Like all hibiscus, Hardy Hibiscus thrives in sun. But unlike the Rose-of-Sharon, it tolerates moist soils. In fact, many of the native Hibiscus species thrive in marshy areas, wetlands, and ditches. Once established, many species and cultivars can withstand dry conditions and even short periods of drought without injury. Cultivars vary greatly in leaf size, leaf dissection, leaf color, flower color, flower size, and mature height.

Hardy Hibiscus Cultivars

The list below is a small sampling of the available cultivars of hardy hibiscus.

Cultivar

Height (feet)

Flower Color

Foliage Color

Angelique

3

White with red eye

Green

Berry Awesome

4

Pink/purple flowers with red eye

Green

Cherry Cheesecake

5-7

White with pink veining and red eye

Green

Copper Queen

4

Pale pink with red veining and red eye

Dark purple

Cranberry Crush

4

Bright red flowers

Green

Disco Belle

3

Red, pink, or white flowers with red eye

Green

Fantasia

3

Rosy pink with dark red eye

Green

Fireball

4

Dark red flowers

Fine textured green

Lord Baltimore

4-5

Red flowers

Green

Midnight Marvel

5-6

Dark red flowers

Dark purple

Perfect Storm

3

Pink with red eye

Dark purple

Peppermint Flare

4

White with red streaks and red eye

Green

Southern Belle

5

Red, pink, white, or bicolor flowers with red eye

Green

Starry Starry Night

4

Pink with darker pink stripes and red eye

Dark purple

Summer Carnival

4

Rosy red flowers

Variegated green pink and white

Summer Storm

7

Pink with red eye

Dark purple

Tie Dye

5

Pink outer petals with white inside and red eye

Green

Turn of the Century

6

Pink and red pinwheel like flowers with red eye

Green


Hardy Hibiscus Summerific Berry Awesome
Hardy Hibiscus Summerific® 'Berry Awesome'  Photo by Aaron Steil

More Information

Authors:
Last reviewed:
July 2023