How to Grow Hawaiian Cotton
Wikimedia Commons
Hawaiian Cotton
Gossypium tomentosum
shrubHawaiian cotton is a rare endemic shrub native to Hawaii's leeward islands, characterized by bright yellow flowers with a deep red or purple center and soft, fluffy white cotton bolls. This slow-growing, drought-tolerant species is endangered in the wild but valued by gardeners and textile enthusiasts for its ornamental beauty and ability to produce spinnable fiber. It represents an important part of Hawaiian botanical heritage and traditional fiber culture.
When should you plant Hawaiian Cotton in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Hawaiian Cotton timeline · Pittsburgh, PA (Zone 6b)
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Plant Hawaiian Cotton
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Hawaiian Cotton
Around Aug 15≈ 120 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Hawaiian Cotton dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 10-11; requires warm, dry conditions year-round
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Get my Hawaiian Cotton timeline →Growth Stages
Seedling
3-4 weeksYoung plant with cotyledons followed by true leaves; growth is initially slow
Keep soil evenly moist but not waterlogged; provide bright light; protect from cold; thin seedlings if necessary
Vegetative Growth
8-12 weeksPlant develops bushy form with deeply lobed leaves; no flowers yet
Reduce watering frequency as plant becomes established; allow drying between waterings; provide full sun; minimal fertilizer needed
Flowering
6-10 weeksLarge, showy yellow flowers with distinctive dark red or purple center emerge on branch tips
Continue full sun exposure; maintain dry conditions; flowers are short-lived (1 day); do not overwater
Boll Development & Maturation
12-16 weeksFertilized flowers drop; green bolls form and gradually enlarge, then change color as they dry
Minimize watering; provide excellent drainage; allow natural drying; bolls are ready when papery and splitting open
Harvest Ready
Ongoing through dry seasonBolls split open naturally, revealing fluffy white cotton fiber ready for harvest
Pick cotton when bolls are fully open; handle gently to avoid damaging fiber; store in dry location
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with insecticidal soap or neem oil; encourage natural predators; avoid excessive nitrogen fertilizer
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Increase humidity slightly with occasional misting; use miticide if severe; improve air circulation
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Use yellow sticky traps; spray with neem oil or insecticidal soap; remove heavily infested leaves
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Hand-pick affected bolls; use Bt (Bacillus thuringiensis) if necessary; encourage natural parasitoid wasps
Uses
Hand-spinning and textile fiber
CraftThe fluffy cotton bolls produce high-quality fiber that can be hand-spun into yarn for weaving, knitting, or other textile crafts. Hawaiian cotton is particularly prized by fiber artists and historically was used by Native Hawaiians for making kapa cloth. [source]
Ornamental flowering shrub
OrnamentalThe bright yellow flowers with deep red centers are highly decorative and bloom prolifically in warm, dry climates. The contrast between the cheerful flowers and developing white cotton bolls makes this a striking landscape specimen. [source]
Pollinator support
WildlifeThe abundant flowers attract native and introduced pollinators, including bees and beneficial insects. Growing Hawaiian cotton supports native Hawaiian insect populations. [source]
Natural fiber for household goods
HouseholdHarvested and processed cotton can be used to make batting for pillows, quilts, and other soft goods, or carded and spun for various household textiles. [source]
Cottonseed oil (historical)
CulinaryWhile not typically cultivated for this purpose today, cotton seeds have been historically processed to produce cottonseed oil for cooking and other applications. [source]
Harvest Tips
Wait until bolls split open naturally, revealing fluffy white cotton. Pick cotton by hand, gently separating fiber from the boll. Harvest in early morning when humidity is lower. Remove bolls that have split open and dried. Cotton is ready when completely white and fluffy, typically 90-120 days after flowering.
Fun Facts
- 🌱 Gossypium tomentosum is found nowhere else in the world except Hawaii's leeward islands, making it a unique endemic species critical to Hawaiian biodiversity conservation.
- 🌱 The genus name Gossypium comes from the Arabic word 'qutn,' reflecting cotton's ancient importance across Mediterranean and Middle Eastern cultures.
- 🌱 Native Hawaiians traditionally used various cotton species and processed fibers with techniques similar to those used for kapa cloth, demonstrating sophisticated textile knowledge long before European contact.
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