Cotton is grown in Florida, particularly in North Florida and the Panhandle, where the warm, sunny conditions of the Southeast allow for commercial production. Historically, Florida was a significant producer of the highly prized, long-staple Sea Island cotton, which was extremely profitable until its decline due to pest and disease pressure. Today, successful cultivation relies on carefully managing the subtropical environment to meet the plant’s specific needs throughout its long growing season.
Climate Requirements and Planting Schedule
Successful cotton cultivation requires a long period of warmth, needing between 180 and 210 frost-free days for the plant to fully mature. Ideal air temperatures for growth range from 70°F to 100°F, though nighttime temperatures above 65°F are important for efficient boll development. Cotton seeds require a minimum soil temperature of 65°F at planting depth for rapid germination, a condition usually met across northern Florida by late April or early May.
Planting timing is crucial to ensure harvest occurs before the peak of the Atlantic hurricane season. Planting in late spring or early summer allows the crop to mature and open bolls during the drier, cooler conditions of late summer and autumn. This strategy prevents heavy tropical rains from damaging lint quality or causing boll rot, maximizing yield potential before the weather becomes less favorable.
Soil Preparation and Nutrient Demands
Cotton performs best in well-drained, deep sandy loam soils, which are prevalent in the Florida Panhandle. The soil’s ability to shed water is a primary concern, as excessive saturation can lead to root diseases and nutrient leaching. Cotton prefers a slightly acidic to neutral soil environment, targeting a pH range between 6.0 and 6.5 to optimize nutrient availability. If the pH is too low, lime must be applied several months before planting to allow the soil chemistry time to adjust.
The plant has high nutritional requirements, especially for nitrogen (N) and potassium (K), which is challenging in Florida’s porous, sandy soils. Nitrogen is applied using a split application strategy, often in two to four increments, starting at the first true leaf stage and stopping before full bloom. This prevents nitrogen from leaching and avoids excessive late-season vegetative growth that delays maturity. Potassium demand peaks during the boll-filling stage, so growers typically apply a portion pre-plant and the remainder as a side-dress application to support fiber quality.
Managing Pests and Disease Vulnerability
The humid, subtropical climate creates a high-pressure environment for cotton pests and diseases. While the successful eradication program has virtually eliminated the devastating boll weevil, new and existing threats require constant vigilance.
Insect Pests
Stink bugs and tarnished plant bugs are the most economically damaging pests, targeting developing squares and bolls during the squaring and flowering stages. Early-season pests like thrips damage seedlings, while late-season pests include the cotton aphid and various lepidopteran caterpillars such as bollworms and armyworms.
Diseases and Nematodes
High humidity exacerbates several damaging fungal diseases, most notably boll rot and hardlock. Boll rot occurs when fungal pathogens colonize the lint of open bolls following wet weather. Hardlock is a condition where the lint fails to fluff out, often caused by the fungus Fusarium verticillioides and worsened by high nitrogen levels. Microscopic parasitic roundworms, such as the root-knot, reniform, and sting nematodes, are a persistent problem in Florida’s sandy soils. These nematodes damage the roots, reducing the plant’s ability to take up water and nutrients, and increase vulnerability to Fusarium wilt disease.
Integrated Pest Management
Management requires an integrated pest management (IPM) approach that relies on regularly scouting fields to monitor pest populations before they exceed economic thresholds. Cultural controls are foundational, including selecting early-maturing cotton varieties to escape peak late-season pest pressure and implementing crop rotation to reduce nematode and disease inoculum. The widespread use of genetically modified cotton varieties that express insecticidal proteins (Bt cotton) has also reduced the need for broad-spectrum insecticide sprays, helping to preserve beneficial insects.