How to Grow Butterfly Milkweed
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Butterfly Milkweed
Asclepias tuberosa
flowerButterfly milkweed is a native North American perennial wildflower known for its vibrant orange, red, or yellow clusters of small flowers that bloom in mid-summer. It is the sole larval food source for monarch butterfly caterpillars and attracts numerous pollinators to the garden. The plant features narrow, lance-shaped leaves and grows as an herbaceous perennial from a deep taproot.
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Example Butterfly Milkweed timeline · Pittsburgh, PA (Zone 6b)
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Plant Butterfly Milkweed
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 Butterfly Milkweed blooms
Mid-to-late summerBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Butterfly Milkweed dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; performs best in zones 4-8
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Seedling
3-4 weeksTiny seedlings with narrow cotyledons emerge from soil; plant focuses on developing deep taproot rather than above-ground growth.
Keep soil consistently moist but not waterlogged. Avoid transplanting if possible due to delicate taproot. Direct seeding is strongly preferred.
Vegetative (Year 1)
8-10 monthsFirst-year plants develop a rosette of narrow, lance-shaped leaves and establish a deep taproot system. Minimal above-ground growth.
Maintain moderate soil moisture as plant establishes root system. Apply mulch lightly around base. Do not fertilize; plant prefers lean soil.
Flowering Preparation (Spring Year 2)
4-6 weeksPlant produces multiple upright stems with lance-shaped leaves arranged alternately; flower buds begin forming at stem tips.
Ensure full sun exposure. Water during dry spells. Once established, reduce watering frequency. Avoid high-nitrogen fertilizers.
Flowering
6-8 weeks (June-August)Dense clusters (umbels) of small five-petaled flowers bloom in shades of orange, red, or yellow at stem tips. Flowers attract butterflies and other pollinators.
Deadhead spent flower clusters to encourage prolonged blooming, though some should be left to set seed. Support tall stems if needed in windy locations.
Seed Pod & Dormancy
8-12 weeks (September-November)After flowering, distinctive elongated seed pods develop. Plants gradually decline as temperatures cool; foliage yellows and dies back to ground.
Allow seed pods to mature and dry on plant for seed dispersal. Cut back dead stems in late fall or early spring. Let seeds self-sow for next year's plants.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Generally beneficial; tolerate their presence as they feed on seeds. Hand-remove only if infestation is severe.
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These are desirable! Plant butterfly milkweed specifically to host them. No control needed.
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Ensure excellent drainage and avoid overwatering. Plant in well-draining soil. Remove and destroy affected plants if rot occurs.
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Provide good air circulation and full sun. Rarely problematic in well-grown plants. Apply sulfur dust if severe.
Uses
Monarch Butterfly Larval Host Plant
WildlifeButterfly milkweed is the sole larval food source for monarch butterfly caterpillars. Planting it is essential for monarch conservation and creating pollinator-friendly gardens. [source]
Pollinator Nectar Source
WildlifeThe vibrant flower clusters attract numerous pollinators including bees, butterflies, hummingbirds, and other beneficial insects throughout the blooming season. [source]
Traditional Native American Medicine
MedicinalHistorically, Native Americans used butterfly milkweed root preparations to treat respiratory ailments and lung conditions. The plant contains cardiac glycosides and has been studied for various medicinal properties. [source]
Cut Flowers & Arrangements
HouseholdThe striking orange flower clusters make attractive cut flowers for fresh arrangements, though they have a relatively short vase life of 1-3 days. [source]
Dried Seed Pod Arrangements
CraftThe distinctive elongated seed pods dry beautifully and can be used in dried flower arrangements and fall decorative displays. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Butterfly milkweed is not harvested for food, but seed pods can be collected in late summer/early fall. Allow pods to dry fully on the plant; they will split open to release feathery seeds. Collect seed pods before heavy rains to prevent seed loss. Seeds can be stored in a cool, dry place for spring planting. Cut flowers last a short time in vases (1-3 days).
Fun Facts
- 🌱 Butterfly milkweed gets its name from the milky latex sap that oozes from broken stems and leaves, which is toxic to many insects but monarch caterpillars have evolved to safely consume it for protection against predators.
- 🌱 The plant's deep taproot can extend 2-3 feet into the soil, making it extremely drought-tolerant once established and nearly impossible to divide or transplant successfully.
- 🌱 Butterfly milkweed is a native wildflower to much of North America and was historically important in ecological restoration; many native plant societies actively promote it for pollinator conservation.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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