Canna is hardy to USDA zones 8-11. They have large leaves that come in green or bronze colors. Cannas are related to bananas and gingers, which is why the leaves resemble those of the banana tree (1). The canna plant can grow up to 6 feet tall and 2 feet wide. It grows best in full sun and in soil that has a pH level ranging from 6.0-7.5. The soil needs to be rich and moist. Canna can be propagated by rhizomes, which are underground stems.
In hardy zones, canna should be started indoors. In the other zones that have longer growing seasons, canna should be planted outside in the summer. They should be spaced 2-4 feet apart, and the rhizomes should be placed 2-3 inches deep in the soil. Cannas need a generous supply of water during the summer, especially in dry conditions. A thin layer of mulch can be added to keep the moisture in. Cannas grow very well in wet areas and can even grow in wetlands that are slightly polluted. The flowers come in a variety of colors. The flower heads should be removed in order to encourage the growth of new flowers. In the winter, when the cannas’ leaves start to turn black, cut the stems to the ground and remove the rhizomes for storage. The rhizomes should be stored in a dry place but should not be allowed to dry out (2).
Medicinal/Culinary Uses of Canna
Canna can be used to treat menstrual pains. The root can be used to treat gonorrhea and amenorrhoea. In Nigeria, people turn the root into a powder and ingest it to treat diarrhea and dysentery (7). They also use the flowers as a medicine for malaria. In other parts of Africa, canna is used in baths to treat fevers, and the flowers have been used to treat eye ailments (5). In Fiji, the plant’s leaves have been used in decoction, which is often given to mothers after they give birth, to cure headaches. A decoction from the plant’s bark is also used to heal wounds and treat against fish poisoning (9). In Costa Rica, the plant’s leaves are used as a diuretic. A paste is made out of canna in Bangladesh to treat tonsillitis. A juice is created with canna in Samoa to treat inflammation. The starch from the roots of canna are used as arrowroots, which can substitute flour or cornstarch. The starch extracted from canna is used to make noodles in Vietnam. The young shoots can be cooked and eaten or added to salads. They have a sweet flavor and fibrous texture (3). The seeds are grounded and added to tortillas in Mexico. In rural areas of India, canna is used in the production of an alcoholic drink called raksi (4).
Significance to Cultural Communities
The plant is native to subtropical and tropical regions of North and South America, from southern United States to Northern Argentina. Fibers from the stem can be spun to create threads like jute (3). Canna seeds are used in musical instruments like the kayamb from Réunion Island, the Hosho from Zimbabwe, and the calabash hula rattle from Hawaii. They are also used to make necklaces and Buddhist rosaries. The leaves can be used to make purple dyes as well as brown papers. They have been used for roofing, wrapping babies, and wrapping food by the U’Wa Indians of Ecuador and Colombia (5). The smoke produced from burning the leaves of canna plants is insecticidal. In Thailand, canna flowers are given as a gift on Father’s Day (4). In India, plant beds of cannas are used to purify grey water and recycle it (6). Georgia O’Keeffe painted a picture of a red canna in 1924 (8).
- Scheper, Jack, and Steve Christman. "Floridata: Canna X Generalis." Floridata: Canna X Generalis. N.p., 19 Oct. 2003. Web. 23 Oct. 2014. <http://www.floridata.com/ref/C/cann_xge.cfm>.
- "Cannas." The Old Farmer's Almanac. Yankee Publishing, n.d. Web. 23 Oct. 2014. <http%3A%2F%2Fwww.almanac.com%2Fplant%2Fcannas>.
- "Canna Indica Indian Shot PFAF Plant Database." Plants for a Future. Plants for a Future, n.d. Web. 23 Oct. 2014. <http://www.pfaf.org/user/plant.aspx?latinname=Canna+indica>.
- Zagar, Ted P. "Herbal Healer: What Is Canna?" NWItimes. N.p., 12 Sept. 2012. Web. 23 Oct. 2014. <http://www.nwitimes.com/niche/get-healthy/healthy-living/herbal-healer-what-is-canna/article_b275f00f-c5ca-5567-af79-4eaa786fea9d.html>.
- Eland, Sue C. "Canna indica." Plant Biographies. N.p., 2008. Web. 14 Oct. 2014. <http://www.plantlives.com/docs/C/Canna_indica.pdf>.
- Vijay, Hema. "Canna Plant Solve Your Water Woes?" The Hindu. The Hindu, 20 July 2013. Web. 30 Oct. 2014. <http://www.thehindu.com/features/homes-and-gardens/canna-plant-solve-your-water-woes/article4931307.ece>.
- Mishra, Sanchalika, Ashutosh Yadav, and Sandeep K. Singh. "A Review on Canna Indica Linn: Pharmacognostic and PharmacologicaI Profile." Jounrnal of Harmonized Research in Pharmacy 2.2 (2013): 131-44. Johr Online. 2013. Web. 23 Oct. 2014. <http://www.johronline.com/issue/20130627-012823.096.pdf>.
- "Georgia O'Keeffe." Red Canna, 1924 by Georgia O’Keefe. N.p., n.d. Web. 22 Oct. 2014. <http://www.georgiaokeeffe.net/red-canna.jsp>.
- Cambie, R. C., and J. Ash. "Fijian Medicinal Plants." Google Books. Csiro Publishing, 1 Jan. 1994. Web. 30 Oct. 2014. <http://books.google.com/books?id=jxvMfprugfAC&pg=PP81&lpg=PP81&dq=canna+indica+medicinal+uses&source=bl&ots=KEcNEy1Bop&sig=6SH_JFOBdkjugnn8kuq7HaP4pBY&hl=en&sa=X&ei=Tvo_VJeJDM-2yASd0YKQDA&ved=0CEsQ6AEwBzgU#v=onepage&q=canna%20indica%20medicinal%20uses&f=false>.