North America Native Plant

Swamp Milkweed

Botanical name: Asclepias incarnata pulchra

USDA symbol: ASINP2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Asclepias incarnata L. var. neoscotica Fernald (ASINN)  âš˜  Asclepias incarnata L. var. pulchra (Ehrh. ex Willd.) Pers. (ASINP)  âš˜  Asclepias pulchra Ehrh. ex Willd. (ASPU13)   

Swamp Milkweed: The Pink-Flowered Pollinator Powerhouse for Wet Spots If you’ve got a soggy spot in your yard that seems impossible to landscape, or you’re passionate about supporting monarch butterflies, swamp milkweed (Asclepias incarnata pulchra) might just be your new best friend. This gorgeous native perennial doesn’t just tolerate wet ...

Swamp Milkweed: The Pink-Flowered Pollinator Powerhouse for Wet Spots

If you’ve got a soggy spot in your yard that seems impossible to landscape, or you’re passionate about supporting monarch butterflies, swamp milkweed (Asclepias incarnata pulchra) might just be your new best friend. This gorgeous native perennial doesn’t just tolerate wet feet – it absolutely thrives with them!

What Makes Swamp Milkweed Special?

Swamp milkweed stands out from its milkweed cousins with its stunning clusters of pink to rose-purple flowers that bloom from mid to late summer. Unlike some of the more aggressive milkweed species, this beauty plays well with others while still packing a serious pollinator punch. As a native plant species found across 22 states from Maine down to Florida and as far west as Texas, it’s perfectly adapted to eastern and central North American growing conditions.

This perennial herb has quite the impressive resume when it comes to synonyms – botanists have shuffled it around under names like Asclepias pulchra and various varieties of Asclepias incarnata over the years. But no matter what you call it, this plant delivers consistent beauty and ecological value.

Why Your Garden (and Local Wildlife) Will Love It

Here’s where swamp milkweed really shines: it’s absolutely essential for monarch butterflies. Not only do adult monarchs nectar on the flowers, but it’s also one of the host plants where they lay their eggs. The caterpillars munch on the leaves, making this plant a monarch nursery right in your backyard!

But monarchs aren’t the only beneficiaries. The fragrant flower clusters attract:

  • Native bees of all sizes
  • Butterflies beyond monarchs
  • Beneficial insects
  • Hummingbirds occasionally visit too

Later in the season, you’ll get the bonus of decorative seed pods that split open to release fluffy seeds – perfect for dried flower arrangements or just enjoying the natural show in your garden.

Perfect Spots for Planting

Swamp milkweed is incredibly versatile when it comes to garden design. It’s perfect for:

  • Rain gardens and bioswales
  • Edges of ponds or water features
  • Native plant gardens
  • Pollinator gardens
  • Naturalized meadow areas
  • Any consistently moist area where other plants struggle

Growing 3-4 feet tall and about 2 feet wide, it provides good vertical structure without overwhelming smaller plants. The upright growth habit makes it an excellent backdrop for shorter wildflowers.

Growing Swamp Milkweed Successfully

The best news? This plant is refreshingly easy to grow. Here’s what it needs to thrive:

Growing Conditions:
Swamp milkweed lives up to its name – it loves moist to wet soil conditions. While it can tolerate some drought once established, it performs best with consistent moisture. It’s happiest in full sun but will tolerate partial shade, though you might get fewer flowers with less light.

USDA Hardiness Zones:
This tough perennial handles zones 3-9, making it suitable for most of the continental United States.

Planting Tips:

  • Plant in spring after the last frost
  • Space plants 18-24 inches apart
  • Choose the wettest spot in your garden – seriously!
  • Amend clay soil with compost, but don’t worry about drainage

Care and Maintenance:

  • Water regularly during dry spells, especially the first year
  • No fertilizer needed – it actually prefers lean soil
  • Deadhead spent flowers if you want to prevent self-seeding
  • Leave seed heads if you want to collect seeds or feed birds
  • Cut back to ground level in late fall or early spring

The Bottom Line

Swamp milkweed is one of those rare plants that checks all the boxes: native heritage, stunning flowers, crucial wildlife value, and practically foolproof growing requirements. If you have a wet area that needs beautifying or you want to create a monarch waystation, this pink-flowered beauty should definitely be on your planting list.

The only downside? Once you see how many butterflies and bees it attracts, you’ll probably want to plant more milkweed species throughout your garden. Consider that a delightful problem to have!

Swamp Milkweed

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Gentianales

Family

Asclepiadaceae Borkh. - Milkweed family

Genus

Asclepias L. - milkweed

Species

Asclepias incarnata L. - swamp milkweed

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA