Cotton, a fiber crop belonging to the Gossypium genus, can thrive in a home garden setting, despite its association with large commercial farms. Cotton is botanically a perennial shrub, but it is typically grown as a warm-weather annual due to its intolerance of frost. The most commonly cultivated fiber types are Gossypium hirsutum (Upland cotton) and Gossypium barbadense (Pima cotton).
Site Selection and Initial Planting
Successful cotton growth requires a long, hot growing season, ideally 5 to 6 months of frost-free weather. Seeds need warm soil to germinate properly, with an optimal temperature range of 75 to 85°F. Germination can occur when soil temperatures consistently reach at least 60°F, but planting into cooler soil can cause poor germination and chilling injury.
The plant thrives in full sun and demands well-draining soil to prevent root rot. Cotton tolerates various soil types, including sandy or clay-loam, but incorporating organic matter improves structure and moisture retention. A slightly acidic to neutral soil pH, around 6.0, is recommended for optimal nutrient uptake.
Seeds should be planted directly outdoors after the last frost date, or started indoors about six weeks prior in cooler climates. Plant the seeds at a shallow depth of 0.5 to 1.5 inches, ensuring firm soil contact. For in-ground planting, space the plants 12 to 18 inches apart. If using containers, choose one at least 12 inches in diameter, or even 36 inches deep for the best root development.
Ongoing Care and Pest Management
Once seedlings emerge, consistent care is needed throughout the vegetative and reproductive stages. Cotton is drought-tolerant but requires deep, infrequent watering to establish a strong root system. Water is particularly important when the plant forms its reproductive structures, known as squares, and later the bolls. Avoid overwatering, which makes plants susceptible to fungal diseases and rot.
Fertilization should support the plant’s different growth phases, ideally starting with a soil test. Nitrogen is important during the initial vegetative growth stage; a side-dressing application is recommended between the first square formation and the first bloom. Potassium is important later in the season, particularly during the boll filling stage, for maximizing fiber quality and yield.
Growers should monitor for common pests, including aphids, spider mites, and bollworms, which damage leaves and developing bolls. Non-chemical strategies are effective for home gardens, such as manually removing pests or using insecticidal soap to control soft-bodied insects. Neem oil can be sprayed to disrupt the growth and reproduction of various cotton pests. Pruning is not strictly required, but topping the main stem encourages the plant to branch out, potentially leading to more flowers and bolls.
Harvesting and Processing the Bolls
The cotton plant enters its reproductive stage about 35 days after planting with the appearance of squares, which develop into hibiscus-like flowers. After pollination, the flowers drop off, and the protective seed capsule, called the boll, develops over the next 50 to 80 days. Because bolls mature and open at different times, the harvest window is staggered over a period of four to six weeks.
Bolls are ready for harvest when they turn dry, hard, and naturally split open, revealing the white, fluffy fiber. This indicates the cotton has dried sufficiently on the plant. Hand-picking involves gently twisting or pulling the fiber from the dried boll, ensuring minimal plant debris is collected.
After harvesting, the cotton fiber must be dried thoroughly in a sheltered location to prevent mold or mildew. The next step is “ginning,” which separates the lint fiber from the seeds. For small amounts, ginning can be done manually by stretching the fiber and teasing the seeds out, or by using a simple roller. The cleaned fiber, or lint, can then be carded to align the fibers and stored until ready to be spun into yarn.