Asclepias tuberosa (Butterfly Milkweed)

Asclepias tuberosa, commonly known as Butterfly Milkweed or Butterfly Weed, is a resilient native wildflower that brings a splash of fiery color to prairies, meadows, and gardens. Adapted to dry, well-drained soils, it thrives in harsh conditions where few other plants flourish. More than just a visual delight, Butterfly Milkweed is an essential nectar source for pollinators, particularly monarch butterflies, making it a valuable addition to any wildlife-friendly landscape.

Milkweed plants belong to the Apocynaceae family which also includes oleander, hoya, plumeria, and the desert rose. These plants play an essential role in supporting biodiversity and pollinators.

Description

Butterfly Milkweed is a bushy, herbaceous perennial prized for its striking clusters of bright orange to yellow-orange flowers, which bloom continuously from late spring through summer. These vibrant, flat-topped umbels sit atop sturdy, upright stems adorned with stiff, lance-shaped leaves. As summer fades, the flowers give way to attractive, spindle-shaped seed pods that add seasonal interest in fall. The lush, deep-green foliage creates a bold contrast, enhancing the brilliance of the cheerful blooms.

Unlike other milkweed species, Butterfly Milkweed does not produce milky sap when cut. Its fiery flowers are a magnet for pollinators, particularly butterflies, drawing monarchs, bees, and hummingbirds throughout the season. With a deep taproot, this resilient wildflower thrives in dry, sandy, or rocky soils, making it an excellent choice for drought-tolerant gardens, meadows, and prairie plantings.

Native Habitat

Butterfly Milkweed is native to eastern and southern North America, where it grows in well-drained, sandy, or rocky soils in dry prairies, open fields, roadsides, and meadows. It thrives in areas with full sun and is well-adapted to drought conditions. Unlike Swamp Milkweed (Asclepias incarnata), which prefers moist soils, Butterfly Milkweed is highly tolerant of dry, infertile soils and does not spread aggressively through rhizomes.

Plant Type and Habit

• Plant Type: Herbaceous perennial
• Growth Habit: Clumping, upright
• Lifespan: Long-lived perennial
• Root System: Deep taproot, making it drought-tolerant but difficult to transplant once established

Size

• Height: 18-24 inches (45-60 cm)
• Spread: 12-18 inches (30-45 cm)

This plant remains relatively compact, making it suitable for smaller garden spaces or meadow plantings. Unlike Common Milkweed (Asclepias syriaca), it does not spread aggressively. However, it may freely self-seed in the landscape if seed pods are not removed before splitting open.

Flowers and Fruits

• Flower Color: Bright orange to reddish-orange
• Bloom Time: Late spring to late summer
• Flower Shape: Small, star-shaped flowers in flat-topped clusters (umbels) at the tips of stems

Butterfly Milkweed is one of the most eye-catching native wildflowers, with its fiery orange blossoms standing out in prairies and gardens. After blooming, it produces elongated, spindle-shaped seed pods (follicles) that mature in late summer and split open to release silky seeds dispersed by wind.

Foliage

• Leaf Shape: Narrow, lanceolate, arranged alternately along the stems
• Leaf Size: 2-6 inches (5-15 cm) long
• Leaf Color: Deep green, turning yellow in the fall

Unlike other milkweed species, Butterfly Milkweed lacks the characteristic milky sap, making it unique among its relatives.

Hardiness

• USDA Zones: 3-9
• Cold Tolerance: Highly cold-hardy, can survive frost and snow
• Drought Tolerance: Excellent, thanks to its deep taproot

This milkweed species is well-adapted to challenging conditions, including poor soils and dry climates.

Uses in the Garden

Ornamental Uses:

• Adds bright color to meadows, prairies, and pollinator gardens
• Works well in wildflower plantings, rock gardens, and sunny borders
• Pairs well with native grasses and perennials such as coneflowers (Echinacea), black-eyed Susans (Rudbeckia), and blazing stars (Liatris).

• Valued for the excellent quality of its cut flowers, whether in bouquets or dried floral arrangements.
• Explore 50 stunning summer wildflowers to brighten your garden

Ecological Uses:

• Milkweed plants are essential for monarch butterfly survival, providing the sole host for their larvae. Over the past 20 years, North America’s monarch population has declined by 90%, making milkweed conservation more critical than ever. By planting milkweed in your own garden, you can help reverse the fortune of these beautiful insects!
• The nectar-rich flowers attract bees, butterflies, and hummingbirds.
• Helps prevent erosion and contributes to native prairie restoration.

Native Americans historically used Butterfly Milkweed for medicinal purposes, particularly to treat respiratory ailments, leading to its common name, “Pleurisy Root.”

Wildlife Value

Butterfly Milkweed is a vital plant for supporting pollinators. Monarch caterpillars rely on its leaves as a food source, while adult butterflies, bees, and hummingbirds are drawn to its nectar-rich flowers. The plant is also used by the Gray Hairstreak (Strymon melinus), Queen (Danaus gilippus), and the Milkweed Tussock Moth (Euchaetes egle).

Discover more plants that attract butterflies.

Toxicity

Although Butterfly Milkweed has a lower toxicity level compared to other milkweed species, caution should still be taken when planting it. The plant contains cardiac glycosides and resinoids, which can cause nausea, vomiting, diarrhea, weakness, and confusion if ingested in large amounts. Toxic parts include flowers, fruits, leaves, roots, seeds, and stems. Harmful to cats, dogs, and horses.

Deer and Rabbit Resistance

Butterfly Milkweed is naturally resistant to deer and rabbits due to its bitter-tasting leaves. However, young plants may still be nibbled on before they develop their full chemical defenses.

Invasiveness

Unlike Common Milkweed, which spreads aggressively through rhizomes, Butterfly Milkweed remains clump-forming and does not take over garden spaces. However, it does self-seed freely if seed pods are not removed before they split.

Why Grow Butterfly Milkweed?

Butterfly Milkweed is a must-have for any pollinator-friendly garden. Its vibrant blooms, adaptability to dry conditions, and critical role in supporting monarch butterflies make it a valuable addition to native landscapes.

Milkweed: Is it Right for Your Garden? Pros and Cons Explained

How to Grow and Care for Butterfly Milkweed

Light

• Prefers full sun (6+ hours of direct sunlight daily). Tolerate some partial shade
• Explore 50 beautiful wildflowers perfect for full sun gardens

Soil

• Well-drained, sandy, or rocky soil
• Tolerates poor, dry soils
• Does not tolerate wet or heavy clay soils

Watering

• Requires moderate watering in the first year to establish roots
• Drought-tolerant once established

Fertilization

• Generally low-maintenance; compost in spring can boost growth

Pruning

• Cut back stems in late fall or early spring to promote fresh growth
• Deadhead spent flowers to encourage reblooming

Overwintering

• No special care needed—cold-hardy in USDA zones 3-9

How to Propagate Butterfly Milkweed

From Seeds

Butterfly Milkweed seeds require cold stratification to break dormancy.

• Store seeds in moist vermiculite at 35–38°F (1.5–3.3°C) for 30 days
• Direct sow seeds in fall or early spring
• Keep soil moist until germination (2-4 weeks)

From Root Cuttings

• Dig up a mature plant in late fall or early spring
• Cut 4-inch (10 cm) sections of the taproot
• Replant in well-drained soil and keep watered

Common Problems and Pests

Butterfly Milkweed is generally pest-resistant, but it may attract aphids. These can be managed by spraying plants with water or encouraging beneficial insects like ladybugs.

Potential issues:

• Crown rot in wet, poorly drained soils
• Rust and leaf spot in humid conditions

Frequently Asked Questions

Where is the best place to plant Butterfly Milkweed?

The best place to plant Butterfly Milkweed (Asclepias tuberosa) is in full sun with well-drained, sandy, or rocky soil. It thrives in dry meadows, prairies, roadsides, and wildflower gardens. Avoid overly wet or compacted soils, as this species is drought-tolerant and prefers conditions where water drains quickly. It is ideal for pollinator gardens, native plant landscapes, and xeriscapes due to its deep taproot and low-maintenance nature.

What milkweed attracts the most butterflies?

The milkweed species that attract the most butterflies, particularly monarch butterflies, include:

• Common Milkweed (Asclepias syriaca) – One of the top choices for monarch caterpillars due to its abundant foliage and nectar-rich flowers.
• Swamp Milkweed (Asclepias incarnata) – A favorite for monarchs, especially in wetter areas; it produces fragrant pink blooms.
• Butterfly Milkweed (Asclepias tuberosa) – Highly attractive to butterflies, but less commonly used as a host plant by monarch caterpillars.
• Showy Milkweed (Asclepias speciosa) – Similar to Common Milkweed, it has fragrant, pinkish-purple flowers and is a key monarch host.

What is the lifespan of Asclepias?

The lifespan of Asclepias (milkweed) depends on the species and growing conditions:

• Perennial species such as Asclepias tuberosa, A. incarnata, and A. syriaca can live 5 to 10+ years in suitable conditions.
• Tropical milkweed (Asclepias curassavica) is a tender perennial that survives year-round in warm climates but behaves as an annual in colder regions, where it does not survive the winter.

Got questions about milkweed? We have the answers!