Gossypium thurberi aka Thurber's Cotton

Gossypium thurberi is a deciduous shrub known as desert cotton. Other names include Arizona wild cotton and Thurber's cotton. It belongs to the mallow family, Malvaceae. Its native range spans central and southern Arizona, New Mexico, Sonora, and Chihuahua. It grows in desert and dry shrubland habitats. These include rocky slopes, canyons, streamside sites, grasslands, and oak woods. Wild plants occur up to 6,000 feet [1,829 metres] above sea level.

This fast-growing shrub has an upright form with several stems. Garden plants reach 4–10 feet [1.2–3 metres] tall. Their spread is 1–4 feet [0.3–1.2 metres]. Gardeners can grow it as a large shrub or small tree. The bark is smooth and light gray. Young stems start green and later turn red. The simple green leaves have soft hairs and a velvety feel. Each leaf has three to five deep lobes with smooth edges. Leaves measure 0.25–0.5 feet [0.08–0.15 metres] long. Their size varies with the water supply. They turn red to deep maroon in fall or winter.

Single, cup-shaped flowers have five petals with pink near their bases. Their color ranges from ivory to pale yellow. Each bloom spans about 0.17 feet [0.05 metres]. Flowers open in May and June, then again in September. Small cotton bolls follow the blooms. These capsules start green and turn brown as they dry. They split into three sections and expose a few cotton fibers. The yield is too small for commercial cotton use. Flowers draw pollinators, while the plant also supports moths and butterflies. These include the royal moth and gray hairstreak.

Desert cotton grows best in full sun but accepts light shade. It needs sandy or rocky soil that drains well. It withstands heat, drought, and dry soil. Keep the soil dry in winter to help it survive. The listed hardiness range covers USDA zones 8a through 10b. Its low upkeep suits dry gardens and naturalized sites. Both the flowers and changing leaf colors add garden interest.

Prune frost-damaged growth in late spring, or trim for shape as needed. Pink bollworm can attack this plant. In the 1930s, people tried to remove it over boll weevil fears. Later findings showed that it did not host that pest. The supplied sources give no food uses or clear safety assessment.