Yes, it’s time for one more native species to take to the air. The great milkweed migration is on.
By late summer, milkweed pods are bursting with mature seeds affixed to bundles of platinum floss that lie damp and orderly, waiting for autumn emancipation. After a killing frost, each pod dries out and splits perfectly along a seam into two boat-like halves, exposing a cache of silk. The wind teases this material from the dry-docked pod halves, launching countless puffy, seed-bearing paratroopers to the wind.
Many farmers and gardeners are not impressed by such a performance, as milkweed can be a real nuisance in some crops. Not only is it a perennial, it spreads quite effectively through its robust root system in addition to its migratory seeds. However, certain butterflies are happy about the white parachutes of autumn.
Though monarch butterflies are thriving in many parts of the world, this is not the case with North American monarchs. Recently, monarch populations on this continent have declined sharply, due in large part to habitat loss in Mexico, where they overwinter, but also because of milkweed scarcity.
Monarchs depend on access to milkweed plants, the sole food source for their caterpillars, along the route from their winter home in Mexico up to the Great Lakes and beyond as they move northward each spring. An increased use of agricultural herbicides, along with continued urban sprawl, have resulted in less milkweed. In addition, monarch caterpillars are being poisoned when insecticide-tainted corn pollen (from genetically modified “Bt corn”) drifts onto the milkweed plants they’re eating.
Farmers and butterflies may soon be playing for the same team, though, because milkweed may become an economically viable crop. Native peoples and settlers used milkweed for food, medicine, fiber and even sugar, and we’ve all heard how its buoyant floss was gathered during World War II and used by the military in life preservers.
But modern research is what has landed our native, latex-bearing “weed” on the economic map. The Agricultural Research Service, a division of the United States Department of Agriculture, has found a number of important new uses for milkweed.
The silky floss is already in use in the textile industry. Companies like the Natural Fibers Corporation of Ogallala, Nebraska use it in comforters and down jackets. One of the main advantages of milkweed floss compared to goose down is that it is hypo-allergenic. It’s also 10% warmer, 20% more durable and 50% more breathable than down. As an added plus, it appeals to consumers who don’t want goods made with animal products. During WWII, schoolchildren gathered floss by hand for military life jackets, but today it can be harvested on a large scale with a slightly modified grain combine.
One of the byproducts of floss production is milkweed seed, which is can’t be fed to livestock because it is poisonous to them. Research done in Illinois and Washington State found a silver lining: milkweed seed toxicity makes it valuable as a pesticide against fall armyworms and certain nematodes which can devastate alfalfa, soybeans, potatoes and many other crops. In one trial, ground milkweed seed, tilled into the soil, killed 97% of destructive nematodes.
The fact that milkweed sap, or latex, is rich in hydrocarbons has been known for decades. Funding from the United States Department of Energy enabled a private Utah-based research firm called Native Plants (subsequently financed by an oil company) to start investigating latex as a source of crude oil.
Before it flowers, milkweed is mowed and baled using conventional farm equipment, and then processed to extract oil. The residue, which is 20% protein, can be used as animal feed. Although at current prices it is not profitable to extract oil from milkweed, that could easily change in the future.
But more work is needed before milkweed hits the mainstream. It turns out that while patches of milkweed thrive on roadsides and in meadows, when it is grown on a large scale as a monoculture, disease becomes a problem.
And then there’s the question of milkweed’s image. According to the founder and CEO of Natural Fibers Corporation, one of his marketing obstacles is that “weed” is half of the plant’s name. Dropping “weed,” however, is out of the question, as there is always a risk the dairy industry may register the word “milk” as an exclusive trademark.
Photo of Common Milkweed Follicle courtesy Wikimedia user H. Zell.