Cotton flowers resemble those of the hibiscus and the other mallows.
This is the immature fruit, a capsule that resembles an okra (Abelmoschus esculentus) pod, another relative in the mallow (Malvaceae) family.
In late autumn, the ripe capsules burst open revealing the fluffy white cotton bolls now ready for ready for harvest.
There are actually 32 species of cotton, genus Gossypium, and five species grown commercially, but upland cotton (G. hirsutum), including its hybrids and genetically modified cultivars, is by far the most commonly grown, and the main source of the fiber we use every day. The cotton plant is a perennial shrub, normally grown as an annual. It can get up to 6 ft (2 m) in height, and develops a semi-woody stem. Upland cotton is a coarse plant with broad, 3-5-lobed leaves, 2-4 in (4-10 cm) long. The flowers are quite attractive, about 3 in (7.5 cm) long, starting out yellow and ageing to purplish pink. The fruit is a capsule about 1.5 in (3.75 cm) long containing numerous seeds surrounded by a whitish tomenta (lint and fuzz). The capsule opens at maturity exposing the seeds with their tomenta which is the cotton boll.
The original wild upland cotton, Gossypium hirsutum, is native to Central America, Mexico and the Caribbean Basin, including South Florida. Other species used locally for fiber are native to Africa, Asia and tropical South America. Cotton is grown commercially wherever summers are long and hot, and autumns are relatively dry. Important cotton growing regions include the southern United States, Egypt, China, India, Brazil, Peru, and Asia Minor.
Culture Light: Cotton is grown commercially in full sun, but you can grow the plant as an ornamental in partial shade. Moisture: Cotton plants need adequate moisture during growth, but the crop needs a dry period as the bolls mature so that they do not decay before harvest. In areas that receive less than about 30 in (75 cm) of rain during the growing season, the crop is irrigated. Hardiness: USDA Zones 8 - 11. In frost free climates upland cotton is a perennial. It is almost always grown as an annual, however. Propagation: Cotton is grown from seed planted after all danger of frost has past. For ornamental use in areas with shorter summers, start cotton seeds indoors a few weeks before setting seedlings out in spring.
A field of cotton in bloom at mid-summer.
A field of ripe South Georgia cotton.
The summertime yellow flowers of upland cotton are showy, looking a lot like its close relative, Hibiscus. The white fluffy cotton bolls are uniquely attractive, persisting throughout the winter even after the leaves have fallen. There is no reason this plant shouldn't be provided a spot in the ornamental garden. Kids and grownups too will be excited when they see firsthand where cotton comes from! Swipe a few seeds the next time you pass a cotton field in September and start a couple plants for your border or perennial bed next spring. If you don't like the idea of swiping, you can rescue a lost cotton boll from along the highway between the cotton field and the cotton gin. Several seed companies sell cotton seeds for the home gardener. A small grouping of cotton plants in the flower border will provide pretty yellow flowers in summer, and look especially attractive in winter when the cotton bolls rest like snow on the brown, leafless skeletons.
Most commercial cotton grown today has been genetically modified with the insertion of bacterial genes that repel insect pests so as to reduce the need for chemical pesticides. The cotton plants are grown in large fields over a long frost-free growing season. Even the Bt genetically altered cotton plants usually need frequent applications of pesticides, often from small airplanes. As autumn approaches, the plants are sprayed with a chemical that causes the leaves to drop. Then machines harvest the cotton bolls. The bolls are then taken to a facility (cotton gin) that combs them to remove the seeds and other debris. Next the cotton is spun into a thin thread. The textiles made from cotton thread are the most widely used cloths in the world. There is evidence of the use of cotton thread from 6000 years ago in India and northern Africa.
Like some other members of the mallow family (including okra, Abelmoschus esculentus), cotton leaves have nectaries, which makes them attractive to marauding deer. (The purpose of the nectaries is probably to attract aphids and the ants that herd them - the ants then ward off insects that might eat the leaves.) The immature cotton fruit looks a lot like an immature okra pod, and the whole cotton plant resembles a hibiscus.