Milkweed in early medicine
Common milkweed (Asclepias syrica) is a North American native plant that grows most anywhere from Canada to Mexico, east of the Rockies. People have been aware of it for generations and it has some surprising uses. Linnaeus named the genus for the Asklepios, the Greek god of medicine because it was part of the herbal pharmacy for thousands of years. Native peoples used the sap, roots, flowers and stems for treatment of gallstones, lung infections, arthritis and even wart removal. However, in reality the plant is toxic. It contains cardiac glycosides which can cause difficulty breathing, dilated pupils and muscle spasms if very much is ingested. The only way the plant can safely be consumed is to only use young shoots and leaves and cook it through several changes of boiling water, which sounds like a lot of work when safer wild foods are available. The good thing is, that the taste is so bitter that chances are, no one will eat enough of it to cause any harm and that goes for pets that like to munch on greenery too. They'll take a taste and move on. Grazing animals might experience problems if large quantities are baled in with their hay, however they tend to avoid it as does Bambi when eating fresh grass. This compound is the same one that makes the monarch caterpillar taste so awful that birds avoid them in favor of other insects.
Early non-medicinal uses for milkweed
Milkweed was more useful in day to day life of the Native Peoples and early settlers. They made cordage and rope from the stems and a type of flax-like cloth from the whole plant. The oil from the seeds made an excellent bug repellent and also a type of prehistoric sunscreen. Milkweed plants (the stems, leaves and seed pods) create a lovely, clear yellow natural dye as well. In more modern times, the fluffy down from the seed pods was an alternative to kapok in World War II life jackets. Kapok is a tropical plant that produces fluffy, cotton-like fibers and was used extensively in early life preservers. During war times the shipments were irregular, or none at all and a huge amount of the substance was needed for the military, so milkweed was a viable alternative. Even today there is a winter coat company offering a milkweed-filled 'down' jacket as vegan alternative to goose down, so there's a lot of potential for useful products from the plant.
Where to find milkweed growing
There are over 100 species of milkweed and most of them share similar growing conditions which are sunny conditions and well-drained soil. However Asclepias syrica is probably one of the most wide-spread species and survives in the most diverse climates. It can be found between USDA Zones 3 and 10, east of the Rockies and that covers a great deal of ground. It has also naturalized in parts of the Pacific Northwest. It prefers disturbed ground and conditions unsuitable for many other plants, which is a good thing because it is what is called a 'fugitive species'. It doesn't compete well with grasses and other meadow and prairie plants and needs a bit of upheaval in the system to be successful. Common milkweed is often found at the edges of agricultural fields and in roadside ditches, which has also contributed to its decline. Farmers spray herbicides and many road departments keep the medians and roadway ditches mowed these days, which prevents the milkweed from forming the colonies they were once known for. This in turn, has decimated the monarch population which relies on milkweed for its survival. Monarch caterpillars can only eat milkweed and will quickly die if are forced to other plants.
Growing milkweed in the home garden
Common milkweed grows successfully in the home garden, however the gardener must be prepared for the insects that flock to it and the ragged appearance it has late in the season. Over 450 insect species use milkweed as food and besides the monarch that we're all aware of, our honeybee also relies on it as a nectar and pollen source. Other bees, butterflies and beetles use the milkweed and that gives the plants a well-chewed look as the season progresses. Some gardeners cut their milkweed plants back in early July after it flowers to produce fresh leaves before the monarchs start laying eggs and the new growth is attractive to the caterpillars anyway. Sometimes aphids invade the plants and it is hard to remove them without harming the beneficial and wanted species. Add a teaspoon of regular dish soap to a quart of water and spray the aphids in early morning. Then rinse with fresh water. That should control the aphids without harming anything else. Common milkweed spreads by seeds and underground fleshy rhizomes. However it is hard to transplant, so if you want to include it in your butterfly and pollinator garden, people usually just sow the seeds in the fall. The seedlings will quickly form a nice colony, just remember that they do not do well when crowded with other species. Once established they are drought tolerant and pretty much kill-proof. Just plant them where you want them to grow and remember that milkweed plants can grow quite tall, sometimes over five feet, so give them a space on the back of the border.