Asclepias syriaca (Common milkweed)

Common milkweed is a member of the Asclepiadaceae (milkweed) family.

It easily adapts to growing in a variety of soils from rocky to clay to sandy to chalky and is often found near the banks or flood plains of lakes, ponds, and waterways, in prairies, forest margins, roadsides, and waste places. In Montana it is often found at the edges of fields near ditches. In other words, it is prolific once it gets established. A single pod normally releases 50 – 100 seeds attached to a white, fluffy coma (“parachute”) that allows wind dispersal.

Common milkweed is nature’s mega food market for insects. Over 450 insects are known to feed on some portion of the plant. Numerous insects are attracted to the nectar-laden flowers and it is not uncommon to see flies, beetles, ants, bees, wasps, and butterflies on the flowers at the same time. Milkweeds contain various levels of cardiac glycoside compounds which render the plants toxic to most insects and animals. (Humans should not ingest!) For some insects, the cardiac glycosides become a defense. They can store them in their tissue which renders them inedible or toxic to other animals. Monarch butterflies use this defense and birds leave them and the caterpillars alone. What the birds do not know is that northern monarchs feeding on common milkweed accumulate relatively little of the toxic compounds and probably would be edible.

Monarch butterflies can be helped by encouraging existing patches and planting new ones. It is the only plant the monarch caterpillar eats, and eggs are laid on the underside of its leaves. The plant grows readily from seed and spreads quickly by deep rhizomes. Because common milkweed can be weedy and difficult to remove, care should be used to establish the plant only in places where spread can be tolerated. If you want to add milkweed to your yard, propagation by cuttings of the tuberous rhizome is easy and reliable.

Less well-known human uses include historical Native American medicinal concoctions for everything from ringworm to temporary sterility and as a source for making strong fiber string. Milkweed is collected in the autumn after the leaves have begun to fall off, the stalks turn gray or tan, and the plant dries up. If the milkweed stems will break off at the ground, it’s time to harvest. The dried stalks are then split open and the fibers are twisted into string. Breaking off as many stalks as possible (or burning) encourages re-sprouting in the spring.

03 Milkweed 2Dried milkweed pods can add interesting lines and texture to a fall flower arrangement so take a walk and look for this prolific plant as Montana’s vegetation dries and turns golden.

Submitted by Elizabeth Waddington