How to Grow ʻElapa
ʻElapa
Asclepias curassavica
flowerʻElapa, commonly known as tropical milkweed or showy milkweed, is a vibrant perennial native to tropical and subtropical regions of the Americas. It produces striking orange and red flowers that attract butterflies and other pollinators. The plant is notable for its role in monarch butterfly life cycles and its ornamental appeal in gardens.
When should you plant ʻElapa in your zone?
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Example ʻElapa timeline · Pittsburgh, PA (Zone 6b)
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Plant ʻElapa
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 ʻElapa blooms
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact ʻElapa dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 9b-11; grown as an annual in cooler zones
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Seedling
2-3 weeksTiny green cotyledons emerge; first true leaves appear narrow and simple
Keep soil consistently moist but not waterlogged; provide bright light; maintain warmth (70-75°F)
Vegetative
4-6 weeksPlant develops multiple stems with elongated, lance-shaped leaves; bushy growth habit forms
Thin seedlings to proper spacing; pinch growing tips to encourage branching; fertilize monthly with balanced fertilizer
Flowering
8-12 weeks or longerDistinctive clusters of small, two-toned flowers appear—bright orange outer petals with red inner corona; flowers arranged in umbels
Deadhead spent flowers to encourage continuous blooming; maintain consistent watering; provide stakes for support if needed
Fruiting/Seed Pod Development
4-6 weeksGreen follicles develop from fertilized flowers; pods elongate and turn brown as they mature; filled with silky-winged seeds
Allow some pods to mature for seed collection; remove others if preventing unwanted self-seeding; do not deadhead if seeds are desired
Harvest/Dormancy
Varies by climateSeeds mature and pods split open, releasing silky seeds; plant may die back in cooler months or regrow from roots
Collect seed pods before they split if harvesting seeds; cut back dead growth; in zones 9b and below, treat as annual
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick if populations are low; use neem oil or insecticidal soap for heavy infestations; encourage natural predators
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Spray with water to dislodge; use neem oil or insecticidal soap; encourage ladybugs and parasitic wasps
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Increase humidity; spray with water; use miticide if severe; ensure adequate air circulation
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Remove by hand; use horticultural oil spray; prune heavily infested branches
Uses
Monarch Butterfly Host Plant
WildlifeʻElapa is a primary host plant for monarch butterfly caterpillars (Danaus plexippus), which feed exclusively on milkweed species. Planting ʻElapa supports monarch conservation and provides essential nutrition for developing caterpillars. [source]
Traditional Hawaiian and Polynesian Use
CulinaryIn Hawaiian and other Pacific island cultures, milkweed has been used traditionally in various preparations. The plant has ethnobotanical significance in traditional medicine practices throughout Polynesia. [source]
Traditional Medicinal Applications
MedicinalʻElapa contains cardiac glycosides and has been used in traditional medicine for various ailments, though modern use requires caution. Herbalists have employed it historically for respiratory and digestive purposes. [source]
Ornamental Garden Plant
OrnamentalThe striking orange and red bicolor flowers make ʻElapa a vibrant addition to tropical, subtropical, and warm temperate gardens. It attracts pollinators and creates dynamic visual interest in landscapes. [source]
Seed Pod Crafts and Floral Arrangements
CraftThe distinctive silky-winged seeds and decorative seed pods are prized for dried arrangements, crafts, and floral displays. The pods create striking natural decorative elements in dried bouquets. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
For seeds, allow pods to dry on the plant until they turn brown and begin to split naturally. Collect pods before they fully dehisce. Store dried seeds in cool, dry conditions. For cut flowers, harvest in early morning when blooms are freshest; flowers last 1-2 weeks in a vase.
Fun Facts
- 🌱 ʻElapa contains toxic cardiac glycosides (cardenolides) that monarch caterpillars sequester for their own defense against predators—the caterpillars are toxic to birds that eat them.
- 🌱 The name 'milkweed' comes from the milky latex sap that oozes from broken stems and leaves, which contains the plant's defensive compounds.
- 🌱 In Hawaiian culture, ʻElapa has traditional significance and is one of several milkweed species found in Hawaiian islands, valued for both ornamental and cultural purposes.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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