Pima cotton is a specialty fiber defined by its Extra-Long Staple (ELS) length, where individual cotton fibers measure at least 1.4 inches. This significantly greater length is what gives Pima its signature characteristics. Fabrics made from ELS cotton are prized for their superior strength, exceptional softness, and a distinct natural luster. Pima cotton comes from the species Gossypium barbadense and represents a very small fraction of the global cotton supply.
Primary Cultivation Areas
Pima cotton production in the United States is highly concentrated within the Southwestern region, limited to just four states. The majority of commercial output is harvested in Arizona and California, with smaller production occurring in New Mexico and Texas. This geographical focus is due to the plant’s specific agronomic needs.
California is the dominant producer, with the San Joaquin Valley serving as the largest cultivation area for American Pima. The valley’s controlled agricultural environment and unique climate allow for the necessary long growing season. In Arizona, while Pima County gave the cotton its name, modern production is centered in counties like Pinal, which benefit from the desert’s intense heat.
Pima cotton accounts for a mere 3% of the nation’s total cotton production. This small scale ensures American Pima remains a premium, specialized crop, distinct from other ELS varieties grown internationally.
Environmental Requirements for Growth
The cultivation of ELS cotton is geographically restricted because the plant requires specific environmental conditions to mature. A long, uninterrupted growing cycle is necessary, demanding at least 200 frost-free days annually for the cotton boll to fully develop its extra-long fibers. Pima cotton thrives in intense heat, with ideal daytime temperatures ranging from 77°F to 95°F during the vegetative and flowering stages.
The arid and semi-arid climates of the Southwestern US are uniquely suited because they allow for sophisticated water management. Pima cotton is primarily grown using controlled irrigation, which is essential to regulate the plant’s growth and maintain fiber quality. Farmers employ techniques like drip irrigation to maximize water efficiency. The preferred soil type is deep, well-drained loamy soil, which prevents waterlogging and encourages extensive root systems.
Distinguishing Pima from Supima
While the terms Pima and Supima are often used interchangeably, they refer to different concepts. Pima cotton is the general classification for cotton derived from the Gossypium barbadense species. Pima cotton can be grown anywhere in the world that meets the strict climatic conditions, such as Peru or Australia.
Supima, a portmanteau for “Superior Pima,” is a trademarked brand name for ELS cotton grown exclusively in the United States. The Supima organization is a non-profit association of American Pima cotton growers that licenses the use of its trademark. The Supima designation guarantees that the product contains 100% American-grown Pima cotton and meets rigorous quality and fiber-length standards. This trademark provides consumers with certified traceability back to US farms, ensuring the fiber’s origin and premium quality.