How to Grow Haleakalā geranium
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Haleakalā geranium
Geranium cuneatum subsp. haleakalanum
flowerA delicate endemic Hawaiian geranium native to the high-altitude volcanic slopes of Haleakalā on Maui. This rare alpine flower produces distinctive magenta to pink flowers with deeply lobed foliage adapted to harsh mountain conditions. It is highly specialized for cool, misty alpine environments and is considered endangered in its native habitat.
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Example Haleakalā geranium timeline · Pittsburgh, PA (Zone 6b)
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Plant Haleakalā geranium
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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First Haleakalā geranium blooms
Around Aug 15≈ 120 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Haleakalā geranium dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 10b-11; requires cool alpine conditions and high humidity
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Get my Haleakalā geranium timeline →Growth Stages
Germination
2-4 weeksTiny seedlings emerge with cotyledons; very delicate and vulnerable
Maintain high humidity (70-80%), cool temperatures (55-65°F), and bright indirect light; use a humidity dome or misting bottle; ensure soil stays moist but never soggy
Seedling
4-6 weeksFirst true leaves appear; plant remains small and fragile with fine foliage
Maintain cool conditions and high humidity; provide bright, filtered light; begin gentle air circulation to prevent damping off; water carefully from below if possible
Vegetative Growth
8-12 weeksPlant develops characteristic deeply lobed foliage; stems strengthen and plant becomes bushier
Maintain cool temperatures (60-70°F); ensure good air circulation; continue high humidity; pinch growing tips to encourage branching; fertilize monthly with dilute, balanced fertilizer
Flowering
6-8 weeks or longer with deadheadingDistinctive magenta to pink flowers with deeply lobed sepals appear at branch tips; blooms are small but showy
Maintain cool, humid conditions; provide bright indirect light; continue consistent moisture; reduce nitrogen fertilizer and increase phosphorus to support flowering; remove spent flowers to encourage continued blooming
Mature Plant
Perennial; can live several years with proper careEstablished plant maintains flowering with proper care; can become woody if left unpruned
Prune lightly to maintain shape and encourage bushiness; maintain consistent cool temperatures and humidity; monitor for pests; provide winter dormancy period with slightly reduced watering if possible
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Inspect regularly; use insecticidal soap spray; maintain good air circulation; isolate affected plants
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Remove with rubbing alcohol on cotton swab; spray with neem oil or insecticidal soap; quarantine infested plants
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Increase humidity to discourage infestation; spray with water to dislodge; use miticide if severe
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Spray with strong water stream; use insecticidal soap; encourage natural predators; apply neem oil if necessary
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Ensure excellent air circulation; avoid overhead watering; reduce humidity if fungal issues appear; apply fungicide if needed; improve drainage to prevent root rot
Uses
Native Hawaiian Pollinator Support
WildlifeSupports endemic Hawaiian insects and pollinators in its native ecosystem. In cultivation, it provides nectar and habitat for native and ornamental pollinators. [source]
Alpine Garden Ornamental
CraftPrized by specialist gardeners for alpine and cool-climate rock gardens. Its delicate magenta flowers and fine foliage add elegant texture to carefully curated plant collections. [source]
Specialty Container Plant
HouseholdExcellent for cool greenhouse cultivation, cool-climate conservatories, and alpine plant collections. Requires controlled environments that replicate its mountain habitat. [source]
Traditional Hawaiian Ethnobotany
MedicinalLike other Geranium species, has potential ethnobotanical significance in Hawaiian traditional uses, though documentation is limited due to its rarity and endemism. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
This is an ornamental flower plant not typically harvested for material use. Enjoy blooms on the plant. If collecting seeds, allow flowers to fade and seed pods to develop; collect ripe seed pods when dry and sow immediately or store in cool, dry conditions
Fun Facts
- 🌱 Haleakalā geranium is found only on the volcanic slopes of Haleakalā (meaning 'House of the Sun' in Hawaiian), one of the world's highest volcanic mountains, where it grows in cloud forests at elevations above 6,000 feet
- 🌱 This geranium is critically endangered in its native habitat with only a few hundred plants remaining in the wild, making it a priority for botanical conservation and native plant propagation programs
- 🌱 Unlike most geraniums grown as common houseplants, Haleakalā geranium is a true alpine specialist and requires consistently cool temperatures and high humidity, making it a challenging but rewarding plant for experienced alpine gardeners
Gardening Terms
New to gardening? Learn about terms used in this guide:
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