A host of hibiscus
Plants we commonly call hibiscus are annuals, perennials and even woody shrubs
When you say hibiscus, most gardeners picture the showy tropical flowering plant that graces many landscapes and patios throughout Arkansas. The flowers come in a wide range of colors and the plants bloom nonstop all summer long. Yet, the tropical hibiscus, Hibiscus rosa-sinensis, isn’t the only hibiscus we can grow in Arkansas.
Hibiscus plants are members of a huge family of plants called Malvaceae or Mallow family, which include okra, cotton and hollyhocks. When we narrow the family down to plants we commonly call hibiscus, we have some annuals, perennials and even woody shrubs to choose from.
HIBISCUS ROSA-SINENSIS
Unless you move the tropical hibiscus into a protected location for the winter, Hibiscus rosa-sinensis would be an annual for Arkansas gardens. The flowers last only one day, but provided the plants get ample sunlight, they usually set enough buds that they will continuously bloom
all summer up until a killing frost in the fall. They thrive in heat and humidity, but do like regular water and fertilization.
Plants are sold in a variety of sizes including some with braided trunks. The flowers are extremely showy and grow on glossy, green leafed plants. If you do overwinter your plants indoors, be sure to cut them back before moving them back outside next summer. They bloom on new growth and need to be repotted annually and cut back by by half or more each season to encourage new growth. Plants with braided stems should be cut above the braided trunks.
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Hardy hibiscus is the common name given to several showy perennial hibiscus varieties. New plant introductions are constantly being released and today’s perennial hibiscus choices can range from plants that are 3 feet tall to 20 feet tall at maturity.
Perennial varieties usually begin blooming in late June to early July and continue to bloom through early fall. Flower color is usually in shades of pink, red or white, while foliage color can be green or red, but the foliage is much thinner, and hairy compared to the tropical form. Shape of the foliage can vary by species from large oval leaves to palmate leaves. All of the perennial forms thrive in full sun and moist conditions. Although they form woody stems, after a frost all of the perennial forms die back to the ground and do not begin new growth until the soil warms up in spring.
HIBISCUS MOSCHEUTOS
The most commonly sold “hardy hibiscus” is Hibiscus moscheutos with large saucer-shaped flowers. Some of the most popular early releases were Lady Baltimore, Lord Baltimore and Disco Belle, but today there are many more to choose from. They have dinner-plate size blooms with large leaves, but mature size can run the gamut from dwarf to tall. Some have burgundy foliage while most have green leaves. The mallow sawfly is a common pest, turning the leaves into lacy skeletons. It doesn’t affect the plants’ growth, but it can detract from their ornamental attributes.
HIBISCUS COCCINEUS
Hibiscus coccineus is commonly called the Texas star hardy hibiscus. This hibiscus will grow up to 8 feet tall and wide in moist, well-drained soils. The flowers are bright red with distinct five petals, looking somewhat like a star. The foliage also looks quite different from other hardy hibiscus, having narrow palmate leaves reminiscent of cannabis, but it is not related.
HIBISCUS MUTABILIS
The latest flowering hardy hibiscus is Hibiscus mutabilis, often called the Confederate Rose. The plants are not reliably winter hardy in the northern tier of our state, but cuttings can be taken before a frost and they easily root during the winter to be replanted outdoors next spring after the soil warms up. This perennial can grow 10 feet tall or more in one growing season. It doesn’t begin to bloom until late September or early October. There are single and double forms, which open pink or white depending on the variety and change to a deep pink or red by the end of the day. Plants will often have three different colored blooms on them at the same time. The foliage looks like cotton, one of their cousin plants in the mallow family.
HIBISCUS SABDARIFFA
If you have ever had red zinger tea, you have been drinking tea made from another annual hibiscus — the Roselle hibiscus — Hibiscus sabdariffa. Native to Africa, this plant produces small yellow flowers but at the base of the flower is a showy red cuplike structure called the calyx. That is what is used in making tea, jam or sauces, and what makes it an ornamental in the garden. In Florida, the color and the tart taste of the fruit has led gardeners to use them as a substitute for cranberries. There are many recipes for Florida “cranberry” sauce using the calyces. Roselle is easily grown from seed and can be planted outdoors in late April or early May. It will not begin to bloom until late summer into fall, but one plant can produce a copious amount of calyces. Save seeds before a frost to replant the following year.
HIBISCUS SYRIACUS
Hibiscus syriacus is a common deciduous shrub commonly called althea or rose of Sharon. These old-fashioned shrubs have made a comeback in recent years with many new introductions. Flower color can range from white, to pink, purple and apricot, with some bi-colored blooms. Flowers can be single or double formed. Flowering typically begins in late May to early June and continues until frost. They do best in full sun to partial shade and are tough plants in the garden. They can be pruned to whatever size your landscape desires. Many have multiple trunks, but they can be trained to a single trunk as well.
HIBISCUS CANNABINUS
An important commercial species is Hibiscus cannabinus or Kenaf. Kenaf is a giant hibiscus native to southern Asia grown as a fiber and oil crop. It is capable of growing up to 20 feet in one year under ideal conditions. Development and commercialization of kenaf and various kenaf-based products in the United States started in the 1940s. More USDA research and industry interest was triggered by high newsprint prices in the late 1970s. Today, most of the world’s kenaf is produced in India and China, but research and development is ongoing in Texas, Mississippi and other southeastern states with an emphasis on newsprint. In 1970 kenaf newsprint was produced in Pine Bluff at the International Paper Company’s mill. The foliage looks a bit like cannabis, thus the species name H. cannabinus.
Hibiscus plants can add a lot of color and interest in the summer through fall gardens. Whether you want a permanent shrub, a perennial plant that dies back to the ground or an annual with long-lasting color, you will find many choices in the hibiscus family.