Hibiscus is a tropical shrub or tree with vibrant trumpet-shaped flowers. Hibiscus grows best in zones 9-10. The plant prefers acidic, moist, well-drained soil. Acidity can be increased by adding potting mix or sphagnum peat moss into soil. Hibiscus also thrives in soil that is rich in potassium and low in phosphorus. Hibiscus thrive in full sun, and indoor plants should be placed in front of sun-facing windows. Although hibiscus requires moist soil, over watering leads to fungal disease. During the winter, hibiscus growth goes dormant, and should only be watered when soil is dry. Hibiscus plants are members of the Mallow family and are either hardy or tropical. Hardy hibiscus can survive the winter, while tropical hibiscus require warmer temperatures and to be transplanted during the winter. Tropical hibiscus requires steady temperatures, with ideal temperatures being between 65 and 75 F. Although hardy hibiscus can survive freezing temperatures, they grow best in warm weather, as cold weather can stunt bud growth (1). Pruning is recommended, and results in a bushier, fuller plant. Pruning is best done in winter when the plant is dormant.
Shrubs are deciduous and grow dark green leaves. Plants in warm areas can grow up to 15 feet tall. Flowers are large, vibrantly colored, and grow over a long season. Flowers grow up to 6 inches in diameter, with colors ranging from yellow to peach to red. Many varieties of hibiscus actually change flower color due to possible variables such as temperature change and amount of sunlight received. The same carotenoids and flavonoids that affect the pigment of hibiscus flowers are sources of vitamins. Carotenoids are found in other orange colored foods such as carrots, squash and pumpkin. Carotenoids levels increase in hot weather, which intensifies the vibrancy of flower color. Carotenoids yield yellow, red and orange pigments. Similarly, anthocyanins yield purple, blue, pink red and black pigments, while flavonols yield pale yellow and white flowers. The health of the soil and care of the plant correlate to color vibrancy, so it is important to maximize the health of hibiscus, as they can be sensitive plants (3).
Cinnamon Grappa hibiscus are short and full, with deep-red showy flowers and glossy green leaves. Cinnamon Grappa grow up to 4 feet in height and 24 inches in width. The plant flowers from midsummer to early fall. Cinnamon Grappa thrives in heat. The plant grows quickly, and the expected lifespan is 5 years (8).
Marshmallow hibiscus’ grow bold white, pink, red and fuchsia flowers. This variety grows well in wet, swampy areas, and is commonly found in marshes in the eastern United States, as well as southern states. The plant grows 3 to 8 feet in height, and blooms from summer to the first frost. The plants die to the ground in winter, and resprout in late spring. In Europe the thick roots are used to harvest mucilage, which is used to make white marshmallow candy (9).
Primary pests of hibiscus include whiteflies, aphids and hibiscus beetles. Whiteflies are especially harmful to the plant, and suck out juices from the underside of leaves. Afterwards, they secrete a substance called honeydew that leads to the growth of a black fungus. Whiteflies are attracted to yellow flowers. Aphids also secrete honeydew, which attracts ants to the plant. Hibiscus beetles are shiny black insects that burrow into the unopened flower, sucking out pollen before it blooms. Females then lay eggs in the bud. Beetles are drawn to white, yellow and pink flowers. Creatures such as frogs, toads, ladybugs and centipedes can protect against invaders.
Culinary and Medicinal Uses
The same carotenoids and flavonoids that affect the pigment of hibiscus flowers are sources of vitamins. Carotenoids are found in other orange colored foods such as carrots, squash and pumpkin. Hibiscus flowers can be made into tea, syrup, jam, and stuffed fritters. They can also be pickled and boiled. Flower flavor is mild, and should be used as soon as it is picked. However, flowers can also last for a few hours in the refrigerator. Flowers can be used as jazzy decorative additions to dishes, such as dips and punches (4). While many variations on hibiscus tea exist, a general recipe is to pour hot water over 1 teaspoon of dried flowers or1 tablespoon of fresh flowers. Fresh flowers can be placed in a glass jar with water and left to steep in the sun. Long steeping may result in a bitter flavor. Hibiscus tea is said to sweeten the breath. Red hibiscus flowers are high in Vitamin C and can be used as a tonic to sooth colds and coughs. Hibiscus has an action on hypertension, and multiple studies have demonstrated its blood-pressure lowering actions (6). Hibiscus can help balance blood sugar levels and maintain healthy cholesterol (7). The flowers are known for their digestive powers, and can produce a laxative effect, as well as calm stomach, intestinal, and uterine spasms. Hibiscus have a similar effect as antibiotics in eliminating worms and bacteria. Other uses include lack of appetite, colds, constipation, irritated stomach, fluid retention, heart disease, and nerve disease (9).
Significance to Cultural Communities
Most hibiscus is sourced from Thailand, China, Sudan and Mexico.The healing power of hibiscus has been harnessed by different cultures for centuries, with each culture having its own variation on hibiscus tea. Jamaica is famous in both Caribbean and Mexican cultures, and makes a sweet, dark ruby-red brew. Jamaica is made with hibiscus blossoms, water, sugar and orange slices. In Cuba, 3 green leaves are steeped for 5 minutes and used to soothe the nervous system. In Filipino culture, 10 dried blossoms are placed in 2 cups of water, then boiled down to 1 cup and used for colds (4). In Egypt and Sudan, dark red tea called karkade is used for its “refrigerant” qualities, or its ability to lower body temperature. In Egypt, medicines from the calyx are used to treat cardiac and nerve diseases, as well as a diuretic. In North Africa, medicines from the calyx are used to treat upper respiratory illnesses such as cough, sore throat, as well as genital problems. Pulp from the leaf is also applied externally to heal wounds. In Europe, hibiscus is commonly used in combination with lemon balm leaf and St. John’s wort in tea to soothe a restless nervous system and insomnia. In Iran, sour hibiscus tea is used for hypertension. In Africa, rope is made from the stalks of the hibiscus plant, and oil is extracted from the seeds (6).
1."Ideal Conditions for Hibiscus Plants." Home Guides. Web. 10 Oct. 2014. <http://homeguides.sfgate.com/ideal-conditions-hibiscus-plants-22386.html>.
2."Plant Care Guides: Hibiscus." National Gardening Association, Web. 10 Oct. 2014. <http://www.garden.org/plantguide/?q=show&id=2133>.
3."The Mystery of Hibiscus Colors." Hidden Valley Hibiscus. Web. 10 Oct. 2014. <http://www.hiddenvalleyhibiscus.com/misc/colors.htm>.
4."Recipes." Australian Native Hibiscus and Hibiscus-Like Species. Web. 14 Oct. 2014. <http://www.hibiscus.org/recipes.php>.
5."Herb Profile: Hibiscus." HerbalGram. American Botanical Council, Web. 14 Oct. 2014. <http://cms.herbalgram.org/herbalgram/issue74/article3102.html?ts=1412968323&signature=6797daeb231c7f80efb2b7f0fc6b76d7>.
6."Gaia Herbs | Plant Intelligence." The Surprising Health Benefits of Hibiscus. Web. 14 Oct. 2014. <http://www.gaiaherbs.com/articles/detail/42/The-Surprising-Health-Benefits-of-Hibiscus>.
7."Cinnamon Grappa Hibiscus (Hibiscus 'Cordials Cinnamon Grappa') at Oakland Nurseries Inc." Oakland Nurseries Plant Finder. Oakland Nurseries, Web. 14 Oct. 2014. <http://plants.oaklandnursery.com/12130001/Plant/4823/Cinnamon_Grappa_Hibiscus>.
8."Denton County Master Gardener Association." Denton County Master Gardener Association. Texas A&M Agrilife Extension, Web. 14 Oct. 2014. <http://dcmga.com/north-texas-gardening/perennials/master-gardener-favorites/marshmallow-hibiscus/>.
9."Hibiscus: Uses, Side Effects, Interactions and Warnings." WebMD. WebMD, Web. 14 Oct. 2014. <http://www.webmd.com/vitamins-supplements/ingredientmono-211-hibiscus.aspx?activeingredientid=211&activeingredientname=hibiscus>.