How to Grow Comet Orchid
Wikimedia Commons
Comet Orchid
Angraecum sesquipedale
flowerAngraecum sesquipedale, commonly known as the Comet Orchid or Darwin's Orchid, is a spectacular epiphytic orchid native to Madagascar featuring pure white, star-shaped flowers with an extraordinarily long nectar spur (up to 12 inches). This monopodial orchid blooms once or twice yearly with fragrant, long-lasting flowers and leathery, strap-like foliage. It is prized by orchid enthusiasts for its exotic beauty and historical significance in orchid breeding.
When should you plant Comet Orchid 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 Comet Orchid timeline · Pittsburgh, PA (Zone 6b)
-
Plant Comet Orchid
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
First Comet Orchid blooms
Mid-to-late summerBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Comet Orchid dates for your own zip code.
Growing Conditions
Soil
Growth Stages
Seedling/Young Plant
6-12 monthsTiny orchid with 2-4 small leaves and developing root system. Plant is fragile and requires consistent conditions
Maintain high humidity (70-80%), consistent warm temperatures (70-80°F), and bright indirect light. Keep medium moist but not waterlogged. Repot only when new growth emerges. Avoid fertilizer initially
Vegetative Growth
2-4 years or until maturePlant develops characteristic long, strap-like, leathery leaves growing upward in a monopodial pattern. Root system expands; aerial roots may develop
Provide bright, indirect light and consistent warmth (75-85°F day, 65-75°F night). Fertilize weekly at half-strength with balanced orchid fertilizer during growing season. Maintain high humidity. Repot every 2-3 years in spring using fresh bark medium. Support with stakes if needed
Blooming Preparation
4-8 weeks before floweringPlant reaches maturity with 4-6+ large leaves. Flower spike begins to emerge from leaf axis, typically in late fall or winter
Provide cooler nights (60-65°F) to trigger flowering. Reduce fertilizer nitrogen and increase phosphorus/potassium. Maintain humidity and bright light. Do not disturb developing spike. Ensure good air circulation to prevent bud drop
Flowering
4-8 weeksPlant produces 1-3 pure white, star-shaped flowers with remarkable 12-inch-long nectar spur. Flowers are highly fragrant, especially at night, and last 4-8 weeks or longer
Maintain stable conditions; avoid moving plant. Continue regular watering and humidity. Reduce fertilizer. Provide 12-14 hours of light daily. Gentle air circulation helps prevent fungal issues. Hand-pollinate with fine brush if desired
Post-Bloom Rest
3-6 monthsFlowers fade and drop. Plant enters rest period with continued leaf growth and root development. Seed pods may develop if pollinated
Resume normal fertilization. Continue bright light and humidity. Water regularly. If seed pods present, allow 8-10 months for maturation before harvesting. Return to normal care cycle to encourage next year's bloom
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Increase humidity to 70%+; spray with water mist or neem oil. Isolate affected plant. Inspect leaves weekly
-
Remove with alcohol-soaked cotton swab. Apply insecticidal soap or neem oil. Repeat every 7-10 days until eliminated. Isolate plant
-
Manually remove with soft brush or alcohol swab. Treat with horticultural oil or neem oil every 7-10 days. Improve air circulation
-
Prevent with excellent drainage and air circulation. Remove affected roots. Repot in fresh medium. Reduce watering frequency. Apply fungicide if severe
-
Remove affected leaves immediately. Improve air circulation and reduce humidity slightly. Isolate plant. Apply copper fungicide if needed. Sterilize cutting tools
Uses
Not Applicable
CulinaryAngraecum sesquipedale has no culinary uses. It is strictly an ornamental plant grown for its exceptional flowers [source]
Cut Flowers & Floral Arrangements
HouseholdThe extraordinary white flowers with 12-inch spurs make stunning, long-lasting cut flower displays and luxury wedding arrangements. A single bloom serves as a dramatic focal point and emits a sweet nighttime fragrance [source]
Botanical Art & Illustration
CraftAngraecum sesquipedale has inspired botanical artists, illustrators, and naturalists for centuries due to its unique morphology and the famous Darwin-Humbold theory about its pollinator. Its distinctive spur structure makes it a subject of scientific and artistic study [source]
Pollinator Attraction & Evolution Study
WildlifeIn its native Madagascar habitat, this orchid is pollinated by a hawkmoth (Xanthopan morganii) with a correspondingly long proboscis, exemplifying co-evolution. Cultivated plants rarely set seed without hand-pollination but demonstrate unique plant-pollinator relationships [source]
Indoor Tropical Aesthetics & Humidity Gardening
HouseholdGrowing Angraecum sesquipedale as a houseplant adds exotic tropical ambiance and requires creating a humid microclimate with other tropical plants, encouraging development of specialized indoor gardening skills and humidity management [source]
Harvest Tips
Angraecum sesquipedale is grown for ornamental flowers, not harvested for consumption. Cut flowers last 4-8 weeks on the plant and several weeks in water. To cut for arrangements, use sterile scissors and cut stem near the base of the flower spike. Leave spike on plant for potential future blooms. Seed pods can be harvested after 8-10 months of maturation if hand-pollinated, then dried for seed collection (advanced propagation technique)
Fun Facts
- 🌱 Charles Darwin predicted the existence of an insect with a 12-inch proboscis after observing this orchid's spur in 1862, decades before the hawkmoth pollinator (Xanthopan morganii) was actually discovered, validating his theory of coevolution
- 🌱 Angraecum sesquipedale is Madagascar's national flower and appears on the country's stamps and currency, symbolizing the island's unique biodiversity and horticultural heritage
- 🌱 This orchid's scientific name 'sesquipedale' literally means 'a foot and a half long,' referring to the remarkable length of its nectar spur, one of the most extreme floral structures in nature
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Comet Orchid planting timeline
Tell us your zip code and we'll calculate exactly when to start Comet Orchid seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Comet Orchid timeline →