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Native Plant Society of Texas

Whorled Milkweed

Asclepias verticillata

Other common name(s):

Eastern Whorled Milkweed

Family:

Apocynaceae (Dogbane Family)

Plant Ecoregion Distribution Map

This map uses data from the US EPA. EPA  servers have been offline frequently so maps may not display. We are working on a solution.

East Central Texas Plains, Gulf Coast Prairies and Marshes, Texas Blackland Prairies, Western Gulf Coastal Plain
Bastrop Lost Pines, Floodplains and Low Terraces2, Northern Post Oak Savanna, Northern Prairie Outliers, San Antonio Prairie, Southern Post Oak Savanna
Northern Humid Gulf Coastal Prairies
Floodplains and Low Terraces1, Northern Blackland Prairie, Southern Blackland Prairie
Flatwoods, Floodplains and Low Terraces3, Pleistocene Fluvial Terraces, Red River Bottomlands, Southern Tertiary Uplands, Tertiary Uplands

Plant Characteristics

Growth Form

Herbaceous

Height

1
to
3
ft.

Spread

1
to
2
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Sand, Clay, Rocky, Dry

Light Requirement

Sun, Part Shade

Water Requirement

Low

Native Habitat

Woodland

Bloom and Attraction

Bloom Color

White, Green

Bloom Season

Summer

Seasonal Interest

Nectar, Pollen, Larval Host

Wildlife Benefit

Butterflies, Bees

Maintenance

Drought tolerant. Easily grown from seed, and will self-seed in the landscape if seed pods are not removed prior to splitting open. Seedlings will germinate right away, but they might not flower until the following year. Plants also spread by rhizomes. Can grow in most soil types, however, it doesn’t do well in overly moist soil. Plant dies back in winter, but the rootstock stays alive until spring. WARNING: all milkweeds are toxic to humans. Propagation: seed, cutting, root division.

Comments

Blooms May-September. Grows in erect, single-stemmed form. The narrow, linear leaves are whorled along the stem. Small, greenish-white flowers occur in flat-topped clusters on the upper part of the stem. Seed pods are smooth and narrower than other milkweeds. Although still listed by some in the Asclepiadaceae Family, the majority of botanical organizations now list it in the Apocynaceae Family. Larval host: Monarch Butterfly.

References

Learn about how to propagate Texas native plants.

Material Treatment Method Collection References
Seed Stratification Milkweed seeds need to go through a cold stratification period. Cold stratification is very important for the germination and growth of Milkweed. It helps break the seeds natural dormancy cycle. To do this, we recommend placing Milkweed seed in a damp paper towel or damp sand in a zip lock bag and place in your fridge for 3 – 6 weeks (30 days). Place in an area of the fridge, where it won’t get damaged. We taped ours to the bottom of a refrigerator shelf. Planting In Spring: Once the 30 days are complete, it’s time to plant the cold stratified Milkweed (asclepias) seeds. We recommend planting in 2-4” peat pots. Fill peat pots ¾ of the way with seed starting potting soil and gently add water. Water should be able to drain through the peat pots. Once the soil is damp, place 1-2 cold stratified seeds into each pot. To finish, place 1/4 inch of soil on top of the seed. Planting In Fall: If you're planting Milkweed seed in the fall, let nature do the cold stratification for you! There is no need to place your seeds in the refrigerator before planting, you can plant seeds directly into the soil after there have been a few frosts in your area. This allows for the seeds to remain dormant for the winter and come up in the early spring. Clear away any existing growth and using your index finger to measure, create 1.5" holes for each Milkweed seed. We recommend spacing seeds about 4-6” apart. Place a seed in each hole and cover. Water thoroughly. Watering: Gently water the planted seed to give additional hydration. The best way to water is from the bottom up. Use a flat pan under the peat pots and add a half inch of water to the bottom of the tray. Don’t over water as it can cause fungus. Water every day or every other day as needed, the best way to test the soil dampness is to touch it. If the soil seems dry then add water; if it’s wet, wait for the soil to dry out to water. Light Requirements: For the next few weeks, make sure the Milkweed is either in a sunny window, in a green house or under a grow light. Milkweed needs lots of sun and warmth to grow. If you’re using a grow light, make sure to lower the bulb closer to the pots or your seedlings may become leggy, as they stretch to the light. In our experiment, this happened to us. Ideally a sturdier stem is better. Cold stratified seeds should germinate and sprout within 10-15 days once planted. In total Milkweed from the day they are cold stratified to growth can take 40 plus days, so be patient! 1)) https://www.americanmeadows.com/products/asclepias-whorled-milkweed-wildflower-seeds#:~:text=We%20suggest%20transplanting%20Milkweed%20when,t%20germinate%20over%2085%20degrees. 2) https://www.gardenia.net/plant/asclepias-verticillata#:~:text=surviving%20winter%20conditions.-,How%20to%20Propagate%20Whorled%20Milkweed,18%E2%80%9324%C2%B0C).
Seed No Treatment Place dry seed (not stratified) in seed starting soil and plant in peat pots under a grow light or in a greenhouse to germinate seeds. The success rate for this is low and more difficult to accomplish. If you choose to use this option it can take months for the seeds to germinate. If you are planting seed outside, we suggest seeding in late fall, and let the Milkweed seed lay on the ground through winter. Milkweed seed will have a long winter of dormancy, so once the sun comes out and the ground warms in the spring, the seeds will germinate on their own. 1) https://www.americanmeadows.com/products/asclepias-whorled-milkweed-wildflower-seeds#:~:text=We%20suggest%20transplanting%20Milkweed%20when,t%20germinate%20over%2085%20degrees. 2) https://www.gardenia.net/plant/asclepias-verticillata#:~:text=surviving%20winter%20conditions.-,How%20to%20Propagate%20Whorled%20Milkweed,18%E2%80%9324%C2%B0C).

About the Region

Fall Symposium 2025 Logo - Teach for the Future

Salado, the location of our Fall 2025 Symposium, lies at the intersection of two ecoregions: the Edwards Plateau (Limestone Cut Plain) and Blackland Prairie (Northern Blackland Prairie).

The Edwards Plateau area is also called the Hill Country; however, this general term covers a much larger area extending farther north. Spring-fed creeks are found throughout the region; deep limestone canyons, rivers, and lakes (reservoirs) are common. Ashe juniper is perhaps the most common woody species found throughout the region. Additional woody species include various species of oak, with live oak (Quercus fusiformis) being the most common. Sycamores (Platanus occidentalis) and bald cypress (Taxodium distichum) border waterways. This area is well known for its spring wildflower displays, though they may be viewed in spring, late summer, and fall, as well. According to Texas Parks and Wildlife, average annual rainfall in the Edwards Plateau ranges from 15 to 34 inches.

The Blackland Prairie extends from the Red River south to San Antonio, bordered on the west by the Edwards Plateau and the Cross Timbers, and on the east by the Post Oak Savannah. Annual rainfall averages 30 to 40 inches, with higher averages to the east. This region is dominated by prairie species. The most common grass species include little bluestem (Schizachyrium scoparium) and Indian grass (Sorghastrum nutans) in the uplands and switchgrass (Panicum virgatum) in the riparian areas and drainages. Common herbaceous flowering plants include salvias, penstemons, and silphiums. This area has suffered greatly from overgrazing and agricultural use. Few intact areas remain, though many of the plants can be found along county roadsides throughout the region.

Our fall Symposium host chapter, the Tonkawa Chapter, includes both of these ecoregions.

Source: Wildflowers of Texas by Michael Eason