What Kind Of Climate Does The Cotton Plant Require?

Cotton (​Gossypium​ spp.) is a tropical plant grown as an annual agricultural crop in hotter regions of the world, including in 17 U.S. states across the South, according to the U.S. Department of Agriculture (USDA) Economic Research Service. Cotton requires soil temperatures above 60 degrees Fahrenheit and a long growing season of five to six months for a good harvest.

While cotton is usually grown for its plant fibers, heirloom varieties of cotton can be grown in the home garden or a pot for beautiful hibiscus-like blooms in whites, yellows, and pinks. At the end of the season, balls of cotton in whites, tans, or greens make a fun material for crafts and flower displays. Though cotton does best in warm climates, you can also start seeds indoors if you live in a cooler region.

Seed companies recommend planting cotton in USDA zones 8 through 10 in home gardens. That's because cotton requires a soil temperature of 65 degrees Fahrenheit to germinate and another four or five months of frost-free temperatures to mature. If air temperatures dip below 60 degrees, the growth of the plant slows. On the other hand, growth can also stop when temperatures top 100 degrees. There are early-season and late-season varieties of cotton for different climates, so check with your local extension office for the best varieties to grow. Some states forbid growing cotton at home or require a permit because of problems with a pest called the boll weevil, which is another good reason to contact your extension office.

If you live in USDA zones 5 through 7, you can extend the growing season by starting cotton seeds indoors four to eight weeks early. Plant your cotton seeds 1/2 inch deep in damp, seed-starting soil and keep the pots or seed-starting tray in a warm, sunny window. As the plants grow larger, transplant them into larger pots with space to accommodate the long tap root the plant will develop. Move the cotton plants outdoors into full sun once temperatures stay above 65 degrees, but bring them back inside on cool nights. After about 45 days, the buds of showy white, yellow, or pink flowers will emerge. The cotton plant will continue flowering until cold temperatures arrive in the fall.

Cotton tolerates many soil types, but will thrive in deeply tilled, crumbly, and rich or well-composted soil. Cotton is drought-tolerant and does not appreciate heavy rains or saturated soils. In fact, heavy rains in spring can lower soil temperature and delay development. But cotton does appreciate regular watering about once a week (two to three times a week for potted plants) until the plants have formed bolls — the seed pods that contain cotton balls. Once the bolls form, stop watering the plant and allow the leaves to brown and the bolls to split open. Now you can harvest your very own cotton balls at home.