Aquatic Milkweed

Aquatic Milkweed

© Pat Mahon
Pamahon, CC BY-SA 4.0 , via Wikimedia Commons

Asclepias perennis
Family: Apocynaceae (Dogbane Family)

Aquatic Milkweed (Asclepias perennis) is a native perennial milkweed species found in wetland habitats across Southeast Texas. Unlike other milkweeds, it thrives in moist to wet soils, making it a perfect addition to rain gardens and riparian restoration projects. It produces delicate white to pale pink flowers that serve as an important nectar source for pollinators, especially monarch butterflies.

• Scientific Name: Asclepias perennis
• Common Names: Aquatic Milkweed, White Swamp Milkweed
• Family: Apocynaceae (Dogbane Family)
• Growth Habit: Herbaceous perennial
• Height: 1-3 feet
• Leaves: Narrow, lance-shaped, dark green
• Flowers: Small, white to pale pink clusters
• Bloom Time: May – October in Southeast Texas
• Wildlife Benefits: Provides nectar for bees and butterflies; a host plant for monarch caterpillars

Habitat & Range in Southeast Texas

Aquatic Milkweed prefers consistently moist or wet soils and is commonly found in:

• Riparian Zones: Along streams, rivers, and pond edges
• Swamps & Wetlands: Thrives in seasonally flooded areas
• Ditches & Low-Lying Areas: Naturalized in moist roadside and meadow conditions

This species is well adapted to wet environments but can also tolerate short dry spells.

Ecological Importance

• Monarch Butterfly Host Plant: Essential for monarch caterpillars
• Pollinator Magnet: Attracts a variety of bees, butterflies, and other beneficial insects
• Erosion Control: Helps stabilize soil along water bodies

Landscaping & Gardening Uses

Aquatic Milkweed is a great choice for gardeners looking to support pollinators while incorporating plants suited for wet or seasonally flooded conditions.

Planting & Care

• Sunlight: Full sun to partial shade
• Soil: Prefers moist to wet soils; tolerates clay and loamy soils
• Water Needs: High; thrives in wet conditions
• Maintenance: Low; cut back in late winter to encourage fresh growth
• Companion Plants: Pairs well with Blue Mistflower (Conoclinium coelestinum), Swamp Sunflower (Helianthus angustifolius), and Cardinal Flower (Lobelia cardinalis)

Fun Facts

• Unlike many milkweeds, Aquatic Milkweed does not have milky sap.
• It is one of the few milkweed species adapted to wetland conditions.
• Monarchs rely on milkweed species like this as a critical food source for their caterpillars.

Conservation & Native Plant Advocacy

As wetlands face habitat loss, Aquatic Milkweed plays a vital role in supporting pollinators and restoring native plant communities. By planting this species, you contribute to monarch conservation and wetland ecosystem health.

Where to Find It