Swamp milkweed (Asclepias incarnata 'Cinderella')
Asclepias incarnata 'Cinderella' (Swamp milkweed) offers showy, fragrant pink flowers and low maintenance, perfect for wet, sunny borders.
Complete Plant Information
Overview
Asclepias incarnata ‘Cinderella’, commonly known as Swamp milkweed, is a standout herbaceous perennial valued for its brilliant summer color and essential role in ecological gardening. This specific cultivar offers exceptionally fragrant, vanilla-scented flower heads featuring deep pink, reflexed petals and contrasting pink to white crowns, adding significant visual interest from July into August. While native to wet environments, the adaptability of Swamp milkweed, especially cultivars like ‘Cinderella’, allows it to thrive in many garden settings that receive consistent moisture.
This plant serves a dual purpose, acting as both a structural element in the landscape and a critical food source. It is highly attractive to butterflies and hummingbirds seeking nectar, and crucially, it supports the larval stage of the monarch butterfly. Low maintenance combined with deep taproots means that established clumps of Asclepias incarnata ‘Cinderella’ require little interference once settled into its preferred moist, sunny location.
Gardeners seeking reliable summer interest and ecological contributions should heavily consider incorporating this variety. The strong vertical structure and continuous blooms of Swamp milkweed make it an excellent choice for rain gardens and borders where steady moisture is naturally present or can be supplied.
Fast Facts
- Plant Family: Apocynaceae
- Plant Type: Herbaceous perennial
- Hardiness Zones: USDA Zones 3-8
- Size at Maturity:
- Height: 2-4 ft
- Spread: 1-3 ft
- Bloom Time: July to August
- Bloom Description: Pink to dark pink with pink to white crowns
- Sun Exposure: Full sun
- Water Needs: Medium to wet
- Maintenance Level: Low
How to Grow
Plant Swamp milkweed in spring or fall in a location that receives full sun exposure throughout the day for the best flowering performance. Although this species thrives in medium to wet soils common in swamps and wet meadows, Asclepias incarnata ‘Cinderella’ is surprisingly adaptable and tolerates average, well-drained soil in cultivation, provided it does not dry out completely. Due to its deep taproots, avoid relocating mature plants; ensure placement is final before planting.
Watering is critical, especially during establishment, as this plant prefers moist to wet conditions. Once established, it handles medium moisture well, but consistent moisture supports vigorous growth. Fertilization is rarely necessary; rich soil or excessive feeding can lead to flopping stems.
Maintenance for this perennial is straightforward and low. Foliage emerges slowly in the spring, so patience is required. Deadheading spent flowers is optional but can tidy the appearance; however, leaving the seed pods intact provides winter interest. Cut back dead stems completely in late fall or early spring before new growth begins.
Landscape Uses
Asclepias incarnata ‘Cinderella’ excels in perennial borders that need height and moisture retention. Its upright habit allows it to function beautifully along stream banks or pond edges, fitting perfectly within a naturalized planting scheme or rain garden design. Using Swamp milkweed in these damp areas helps intercept runoff and manage water levels naturally.
For structural interest, pair the 2-4 ft height of Asclepias incarnata ‘Cinderella’ with shorter, moisture-loving perennials like cardinal flower or astilbes, or taller companions like Joe-Pye Weed, creating layered habitat gardens. This plant naturally integrates well into meadow or prairie-style designs where its need for full sun and moisture is easily met. Ensure that its placement allows easy viewing for enjoying the significant butterfly activity it attracts.
Standout Features
Flower Qualities
- Showy
- Fragrant
- Good Cut
Noteworthy Characteristics
Asclepias incarnata, commonly called swamp milkweed, is an erect, clump-forming, Missouri native plant which is commonly found in swamps, river bottomlands and wet meadows throughout the State. Small, fragrant, pink to mauve flowers appear in tight clusters at the stem ends in summer, featuring five reflexed petals and an elevated central crown. Flowers are very attractive to butterflies and hummingbirds as a nectar source, and Swamp milkweed is also a vital food source for the larval stage of monarch butterflies. The ‘Cinderella’ cultivar is noted for its distinct vanilla-scented flower heads, growing to heights between 2 to 4 ft.
Tolerances
- Deer
- Clay Soil
- Wet Soil
Potential Problems
This variety of Swamp milkweed rarely confronts serious pest or disease issues, which adds significantly to its low-maintenance appeal. Routine vigilance should focus on ensuring adequate moisture, particularly during hot, dry spells if planted outside its preferred wet meadow conditions. If planting occurs in drier, average soil, monitor watering closely during the first year to secure the deep taproot system.
Frequently Asked Questions
What hardiness zones is Swamp milkweed suitable for?
Asclepias incarnata ‘Cinderella’ is highly robust, thriving well within USDA Zones 3 through 8.
How large does Swamp milkweed grow?
This perennial typically reaches a height between 2 to 4 feet, spreading moderately to 1-3 feet wide.
What sun exposure does Asclepias incarnata ‘Cinderella’ need?
This plant performs best and blooms profusely when situated in full sun.
When does Asclepias incarnata ‘Cinderella’ bloom?
Swamp milkweed blooms during the peak of summer, generally from July to August, showcasing attractive pink to dark pink flowers with pink to white crowns.
Conclusion
The combination of its easy care, tolerance for moist soil, and significant ecological value makes Asclepias incarnata ‘Cinderella’ an indispensable garden feature. Providing critical nectar and host support for monarch butterflies, this Swamp milkweed cultivar ensures a lively summer landscape. Before planting, confirm your site receives full sun and has the medium to wet conditions this beautiful perennial prefers.
Companion Planting
When designing a vibrant, moist garden setting, consider pairing Swamp milkweed with other moisture-loving natives that share cultural needs. Tall grass varieties, such as Switchgrass (Panicum virgatum), offer excellent vertical contrast to the clumping habit of Asclepias incarnata ‘Cinderella’ while respecting its full sun requirement. Similarly, placement near Blue Flag Iris (Iris versicolor) can enhance interest near water edges, as both species tolerate fluctuating wet conditions.
A design incorporating these companions leverages the native ecology of wet meadows, providing continuous blooms and varied textures that support local wildlife populations throughout the season. Since Swamp milkweed has long, deep roots, it stabilizes banks well while its neighbors fill in the middle and front layers of the border.
Wildlife Benefits of Asclepias incarnata ‘Cinderella’
The primary draw of planting Asclepias incarnata ‘Cinderella’ is its unparalleled benefit to pollinator populations. As a true milkweed, it is the sole host plant for Monarch butterfly caterpillars, making its inclusion non-negotiable for a comprehensive butterfly garden. Ensure you allow some seed pods to mature so the next generation has resources.
Beyond monarchs, the clusters of fragrant, pink flowers are magnets for many other beneficial insects. Hummingbirds are frequent visitors, drawn to the nectar-rich blooms throughout mid to late summer. Planting multiple specimens of this Swamp milkweed cultivar will maximize the area’s attractiveness to nectar feeders when many other spring bloomers have faded.
