Description & Overview
Whorled Milkweed is a pretty and rather delicate-looking native perennial that does best in dry, disturbed soils. Its narrow leaves set it apart from other milkweed species. When not in bloom, it is quite possible to look at this plant and pass it over as some ‘ole’ weed’, but if the foliage is crushed or torn it will exude the toxic milky-white latex characteristic of this genus, giving itself away. The tops of the stems hold small umbels of pretty little white flowers that are relished by pollinators from June to September.
Whorled Milkweed does best in sandy, dry soils. In nature, it is found in dry prairies, slopes, fields, open woods, and roadsides. As a pioneer species, it is happiest paving the way on neglected, exposed soils with low nutrients and little competition. Yes, I know, sounds like a dream to some of us! Just be careful, because when it gets all the above it can spread rather quickly, though, maybe that is still a dream for some!
Restore and Naturalize: Use this plant in restoration projects for dry prairies and meadows or simply to naturalize a neglected plot of land.
Pollinator Project: Milkweed is a necessity for any butterfly garden as it is the host plant of the Monarch butterfly. Hummingbirds love this plant so it would be a good fit for a garden built with birds in mind. When landscaping, consider using Whorled Milkweed as a border or foreground plant due to its smaller size. With the delicate-looking leaves and petite white flowers, they would also look striking planted in groups in a flower bed.
Some sources have stated that Whorled Milkweed is the most toxic of all milkweeds. For this reason, it is seldom found in pastures used by cattle and other grazing livestock as it is culled out by their caretakers. The latex sap is also toxic to humans, horses, dogs, cats, and likely many other mammals as well. Whorled Milkweed will not be bothered by deer.
Whorled Milkweed is one of many perennials in the genus Asclepias that is a larval host to the Monarch Butterfly. Monarchs lay eggs on milkweed plants and the caterpillar feeds on these plants exclusively until it chrysalises. The Monarch population has decreased dramatically in recent years and the belief is that this is due to the decrease in available milkweed because of habitat fragmentation and destruction for development. Plant more Milkweed!
Flowers also attract many types of Halictid bees as well as honeybees, many wasps, flies, skippers, moths, and butterflies. Small Milkweed Bug, Milkweed Leaf Beetle, and Yellow Milkweed Aphid feed on the foliage.
Hummingbirds are attracted to the flowers and use the fibers from the seeds as nesting material.
Whorled Milkweed will propagate by seed and by underground stems called “stolons.” If you wish to prevent spread, deadhead the flowers after they are done blooming before the pods release their seeds. They may need to be thinned out on occasion, but preventing self-seeding helps considerably.
As an early succession species, Whorled Milkweed naturally spreads into spaces that are not yet occupied and may be outcompeted by other encroaching perennials. Use this characteristic to your advantage! Thin out the area around them to provide space so they can thrive and spread or restrict growth by allowing surrounding plants to create a barrier to slow their spread to unwanted areas. This, as well as deadheading, will help to manage their numbers.
There are no serious diseases or pests associated with Whorled Milkweed. They may occasionally get Aphids along the stem, but this is not fatal.
The dried seed pods of Whorled Milkweed are prized among florists for use in floral arrangements. If you are deadheading them to control their population and consider yourself crafty then it is time to get creative!
All parts of the plant are toxic in large quantities. Monarch caterpillars and butterflies have evolved the ability to digest milkweed despite its toxicity. Caterpillars and butterflies are also toxic to potential predators because they fed on milkweed leaves during their larval stage.
Name: The genus name Asclepias was derived from the Greek god, Asklepios, who was the god of healing and medicine. Several species of this genus have been used by people from many cultures around the world to treat a whole host of ailments concerning the human body’s cardiac, digestive, and respiratory systems. This plant has been relied on heavily for centuries, if not millennia.
The species name verticillata roots in the Latin word, ‘verticillatus,’ which means “whorled.” This alludes to the leaves of Whorled Milkweed. Each node along the stem has 3 to 6-inch long narrow leaves that grow out from the stem, like rays of the sun in a child’s picture. The scientific descriptor for this leaf growth pattern is “whorled.”
Historical Uses: Despite the many mentions of its toxicity, this plant was cooked and eaten by several Native American tribes. Some records indicate that the stems and leaves were cooked and eaten. Its latex was used in a kind of chewing gum, while the flowers were eaten fresh or incorporated into dishes. While it is true that some modern-day foragers venture to add parts of the plant into dishes, others heed the warning of potential toxicity and steer clear.
The seed pods contain a fiber that has been used to make baskets, cordage, and even bowstrings. Some U.S. companies use milkweed seed fluff to make hypoallergenic pillows!
In summary, all parts of milkweed have been used historically not only for medicinal purposes, but as a food source, and as raw material to create many objects that would have been vital to living everyday life in the pre-modern era. That is one valuable plant!
Perennials that attract pollinators and enjoy dry to average soils include Blue Giant Hyssop, Rough Blazing Star, Stiff Coreopsis, Butterflyweed, Prairie Smoke, Prairie Phlox, Hairy Wild Petunia, and Prairie Dropseed. Shrubs such as Common Ninebark and St. John’s Wort add variation in size and shape and attract pollinators as well.