Common Milkweed

Asclepias Genus

Silkweed, Butterfly Flower, Silky swallow-wort

Description

Common milkweed is a medium-height plant, ranging from 3-5 feet with thick, broad, green leaves that circle their way up the thin, green stem. Small violet and pale pink flowers that are arranged in small spherical balls, periodically placed along the plants stem. Each cluster consists of roughly 30 pink flowers in the bunch, which each flower contains five petals. Distinct green, soft, spiky pods form during the late spring and summer, and in late fall they begin to dry out and become light brown, hard, and they split open. During fall, the plant’s green attributes fade with hints of brown, and the pale pink bunches of flowers are no longer present.

Cultural

Common milkweed had major historical significance. Native cultures and early pioneers utilized the plant as a food source, although cautious preparation is necessary. It was a valued medicinal plant in the treatment of asthma, kidney and gallstones, ringworm and warts[1], also used as an emetic, diuretic, laxative and contraceptive. Along with the medicinal uses, the silk from the pods can be used as a fiber in rope or fabric. While the plant has beneficial properties and attributes, they are not commonly utilized for medicinal purposes to this day.

Uses

Common milkweed has toxic properties to humans, but is utilized by all aspects of nature – providing shelter, food, and protection to over 450 insects, prominently monarch butterflies and caterpillars. Many insects process the plant’s toxic cardiac glycosides, making them inedible to predators. Monarch butterflies are the most prominent insect to utilize the plant’s toxic properties against predators. With the national population of monarch butterflies decreasing, this plant can assist in increasing their population.

Growing Conditions

Common milkweed strives in dry to medium dry soil and is adaptable to grow in various environments. It’s habitat ranges from pastures, roadsides, ditches, croplands and old fields. The plant requires adequate sunlight, however it’s well adaptable to its environment. Due to its ability to disperse 200 fluffy windborne seeds, it’s able to populate large areas. When growing the plant, the seeds must undergo cold stratification, a naturally occurring process where a seed freezes over winter and thaws during spring. The process can be replicated by placing seeds on a damp paper towel and leaving them in a freezer for a month. It can be defined as a “fugitive species”, a plant whose appearance and persistence is dependent on disturbance due to its inability to compete with other vegetation[2].

Potential Problems & Concerns

Seasonally, the plant attracts pests called, “milkweed bugs”, due to their association with eating and damaging the plant. These pests are omnivores, meaning they will also eat monarch eggs and other caterpillars beneficial to the plant. Insecticidal soap can be used to deter pests but will also deter monarch butterflies from utilizing the plant. These bugs are not problematic to the ecosystem and should be left alone if there is adequate amounts of the plant to sustain itself. Snails and other bugs may be problematic to the plant’s life. To reduce this, use Epsom salt and ensure the areas of salt are generously watered in order to prevent harm to monarch caterpillars. Since the plant is a fugitive species, it has the ability to reproduce rapidly and undesirably, which can be managed by harvesting the pods prior to their splitting.

Printable Factsheet

TechnicalFactSheet_CommonMilkweed

Prepared By: Link Hendricks

Created in collaboration with the UWGB Office of Sustainability, Fall 2022. For any questions, concerns, or corrections, please contact Kristopher Purzycki (English & Humanities) at purzyckk@uwgb.edu.

References

[1] Steve, Allen, “Common Milkweed: A Plant of Many Virtues”, published July 1, 2015, https://loudounwildlife.org/2015/07/common-milkweed-a-plant-of-many-virtues/

[2] “Asclepias Syriaca (Common Milkweed),” Lady Bird Johnson Wildflower Center, last modified September 8, 2020,  https://www.wildflower.org/plants/result.php?id_plant=ASSY