Asclepias incarnata – Swamp Milkweed (Rose Milkweed)

Short Product Description

Swamp Milkweed (Asclepias incarnata)—a native, fragrant milkweed for rain gardens and pond edges; Monarch host plant with rosy summer blooms; prefers moist–wet soils; Zones 3–9.

North American Native
Hardiness Zone – 3–9
Sun – Full sun to light part sun
Moisture – Moist to wet (not drought tolerant)
Size – 3–5′ height; 2–3′ spread

Available: #1 Gallon, 4″, DP-50 Plug

Comments

Monarch host; heavy pollinator draw
Ideal for rain gardens and wet soils

Swamp Milkweed (Asclepias incarnata) Profile and Traits

Product Description

Asclepias incarnata (Swamp Milkweed / Rose Milkweed) is a showy native perennial tailored for rain gardens, wet meadows, and pond margins. Slender, upright stems carry narrow leaves and clusters of fragrant pink to rose flowers in mid–late summer that bring a flurry of pollinators. As a host plant for Monarch butterfly caterpillars, it supports every stage of the Monarch life cycle while providing nectar to bees and butterflies. Thrives in consistently moist to wet soils, yet adapts to average garden conditions with regular water—delivering color, habitat, and long-season interest with minimal fuss.

Quick-Glance Specs

Attribute	Details
Botanical Name	Asclepias incarnata
Common Name	Swamp Milkweed; Rose Milkweed
Plant Type	Native perennial wildflower (milkweed)
Native/Non-native	Native to North America
Hardiness Zone	3–9
Sun Exposure	Full sun to light part sun (best flowering in sun)
Moisture	Moist to wet; tolerates periodic inundation
Mature Height	3–5 ft (site dependent)
Mature Spread	2–3 ft clump
Growth Habit	Upright, clumping; deep root system
Growth Rate	Moderate
Fragrance	Yes—sweet/vanilla-like scent
Bloom Time	Mid-summer to early fall
Seasonal Interest	Long bloom; upright seed pods with silky floss; winter stems
Foliage & Features	Narrow leaves; rosy-pink flower umbels; decorative pods
Landscape Features	Monarch host plant, heavy pollinator draw; rain-garden performer
Landscape Uses	Rain gardens, wet meadows, pond/stream edges, perennial borders
Soil	Rich loam or clay-loam; adapts to average soils with irrigation
Water Needs	Medium (keep evenly moist; not drought-loving)
Maintenance	Low; deadhead for tidiness/control; cut back late winter/early spring
Deer/Pest Resistance	Generally deer resistant (bitter latex sap)

Container Friendly	Yes—in large, moisture-retentive containers
Recommended Spacing	18–24″ on center

Care & Growing Information

Site & Light: Plant in full sun for strongest stems and heaviest bloom; accepts light part sun in hot climates.
Soil & Water: Prefers moist to wet soils (loam or clay-loam). In average beds, supply regular irrigation—avoid prolonged drought.
Planting: Set crowns level with soil; space 18–24″ for airflow. Mulch lightly (keep mulch off crowns) to conserve moisture.
Maintenance: Deadhead to extend bloom and limit self-seeding, or leave pods for wildlife/aesthetics. Cut back to 4–6″ in late winter/early spring.
Notes: Milky latex sap can irritate skin and is toxic if ingested—wear gloves when cutting.

Key Features

Monarch butterfly host plant and top-tier pollinator magnet
Fragrant rose-pink blooms mid–late season
Excellent for rain gardens and moisture-retentive sites
Deer resistant; stands upright with minimal staking in sun
Attractive seed pods and winter structure

Problems

Generally easy. Oleander aphids and milkweed bugs may appear—control with strong water sprays or targeted, pollinator-safe methods (avoid systemic insecticides). Occasional leaf spot in stagnant humidity—ensure spacing. Not drought tolerant.

Uses in the Landscape

Rain gardens and bioswales with consistent moisture
Wet meadows and shoreline edges with seasonal inundation
Pollinator gardens and native plantings for habitat support
Mixed borders needing mid-height color and long bloom

Availability / Ordering

Sizes Offered: #1 Gallon, 4″, DP-50 Plug
Recommended Spacing: 18–24″ for cohesive drifts and airflow.

Why You’ll Love It

Combines ecosystem value (Monarch host) with fragrance and reliable bloom
Thrives where many perennials struggle—moist to wet soils
Simple annual cutback and occasional deadheading keep it showy

Quick Highlights

A fragrant, pollinator-powerhouse for moist sites—Asclepias incarnata brings rosy blooms, Monarch habitat, and low-maintenance performance to rain gardens and wet borders.

Additional information

Size	#1 Gallon, 4", DP50 Plug

Monarch Butterfly Habitat

Swamp Milkweed (Asclepias incarnata) is a crucial native plant for supporting Monarch butterfly populations. As a primary host plant, it provides the essential food source for Monarch caterpillars. Female Monarchs exclusively lay their eggs on milkweed plants, and the emerging larvae feed solely on its leaves before pupating into butterflies.

By incorporating Swamp Milkweed into your garden, you directly contribute to the conservation of Monarchs, helping to sustain their migratory patterns. Its presence in a landscape can significantly increase the number of Monarchs observed, offering a rewarding experience for gardeners and nature enthusiasts alike.

Rain Garden Benefits

The Swamp Milkweed is an exceptional choice for rain gardens due to its natural affinity for moist to wet conditions. Its robust root system helps to absorb excess water, thus mitigating runoff and filtering pollutants before they reach local waterways. This makes it an environmentally beneficial addition to any landscape aiming for sustainable water management.

Its ability to thrive in saturated soils means it can effectively manage stormwater, reducing the risk of localized flooding and erosion. The plant's aesthetic appeal, with its attractive pink blooms, also adds beauty to functional rain garden designs, blending ecological benefits with visual appeal.

Pollinator Attraction

Beyond its role as a Monarch host plant, Asclepias incarnata is a magnet for a wide array of beneficial pollinators. Its nectar-rich flowers provide a vital food source throughout the blooming season, attracting bees, butterflies, and other beneficial insects that play a critical role in pollination and ecosystem health.

The continuous bloom from mid-summer to early fall ensures a sustained food supply for these pollinators. This makes Swamp Milkweed an invaluable component of any pollinator garden, contributing to biodiversity and supporting healthy ecological systems within your garden and beyond.

Soil and Water Requirements

Asclepias incarnata thrives in moist to wet soils and prefers full sun to light part sun conditions for optimal growth and flowering. It is not drought-tolerant and requires consistent moisture, making it ideal for areas like rain gardens, pond edges, and wet meadows where water retention is naturally high.

The plant adapts well to rich loam or clay-loam soils. While it prefers consistent moisture, it can tolerate periodic inundation, which is a key characteristic that makes it suitable for wetland environments and areas prone to waterlogging. Proper site selection is crucial for its success.

Asclepias incarnata – Swamp Milkweed (Rose Milkweed)