In the fall of 1944, the fate of thousands of sailors rested, in part, on a weed that children were gathering along ditches, in onion sacks. Far from the din of battle, a silent army of schoolchildren, scouts and 4-H club members combed the fields of some thirty American states and Canada, picking milkweed pods. Their harvest would float under the arms of the crews of the U.S. Navy. Here is how a plant despised by farmers became, for the length of a war, an unlikely hero.
When the kapok ran out
Before the war, the U.S. Navy's life vests slept full of kapok, a light, buoyant fibre taken from a tropical tree and grown almost exclusively in Southeast Asia, mainly on Java, in the Dutch East Indies, today's Indonesia. The supply seemed eternal. It collapsed in a single season. In early 1942, the Japanese advance on Java abruptly closed the kapok route to American ports. Overnight, the world's foremost navy found itself without the fibre that kept its men on the surface, at the very moment the war was spreading across two oceans.
A replacement was needed, and it was needed yesterday. In their laboratories, Navy engineers tested dozens of buoyant materials one by one: plant fibres, foams, corks. Nearly all of them failed: too heavy, too fragile, quickly waterlogged with salt water. Then an unlikely candidate stood out, a plant no one would have thought of cultivating, the one that grew on its own in the ditches and fallow fields of North America: milkweed.
A fibre that floats
Milkweed's secret lies in the structure of its floss. Each filament is a fine hollow tube whose wall is coated with a thin layer of natural wax. The tube traps air, the wax repels water, and the whole floats with remarkable stubbornness. According to Navy tests, a single pound of this floss kept a 150-pound man afloat. The fibre proved as warm as wool but far lighter, and more buoyant than cork. On paper, it was the ideal solution.
There remained the obstacle that would complicate everything: hundreds of tons of it had to be produced, without time to cultivate a single hectare. Milkweed floss is not harvested like cotton, in orderly fields. It lay dormant in millions of pods scattered at random across the landscape, and no supply chain existed to process it. A Chicago physician would take on this problem with the tenacity of a missionary.
Boris Berkman, the man of a single plant
Dr. Boris Berkman was a physician and inventor in Chicago, and he believed in milkweed the way one believes in a cause. Well before the war, he had convinced himself that this scorned plant held an exceptional fibre, and as early as 1939 he had filed a patent for a "milkweed gin," a machine designed to separate the floss from the seeds. Over his lifetime, he accumulated more than twenty milkweed-related patents, from factory processes to the most unexpected ideas, ear muffs or coat linings.
When the kapok ran out, his hour had come. In March 1942, he brought his fibre before the House agriculture committee, badgered the Navy and won the right to put it to the test. The trials proved him right. The Navy announced it wanted a million pounds of floss, a figure so dizzying that, as one newspaper of the day admitted, "nobody believed it." Berkman believed it enough to found the Milkweed Floss Corporation of America and take its helm. The war was finally giving his plant the stage it had been waiting for.
"Two bags save one life"
Growing milkweed in time was out of reach. So the wild plant would be harvested. Starting in 1943, and above all in the fall of 1944, a huge national campaign enlisted some thirty states east of the Rockies and Canada. The men were at the front, the women in the factories; that left the children. Schoolchildren, Boy Scouts, Girl Scouts and 4-H clubs set out, bags in hand, behind a slogan of fearsome efficiency: "Two bags save one life." Never had a phrase said so simply that an armful of pods could be worth a man's life.
The deal was clear. Pickers were handed mesh onion sacks, and the government paid fifteen cents per full sack, five more if the pods were well dried. A sack held six to eight hundred pods; two were needed for a single vest. The instructions left no room for approximation: pick the ripe, browning pods while still closed, before the wind carried off the floss; never gather them wet. The mesh of the sack had its purpose: to let air through. The harvest was then hung astride fences, in the sun and wind, during the day, so the floss would dry without moulding.
Petoskey, milkweed capital of the world
All of this harvest converged on a single point on the globe: the small town of Petoskey, in northern Michigan, chosen because the shores of Lake Michigan were overrun with milkweed and a port and a railway conveniently met there. Contrary to a persistent legend, the plant did not set up in a sawmill, but in the requisitioned premises of a large local lumber and building supply company, Preston Feather & Sons, handed over to the Milkweed Floss Corporation of America.
Inside, the ingenuity bordered on inspired tinkering. A large kiln swallowed pods from every corner of the country, since other states also shipped their harvest to Petoskey. Then seven gins, the famous milkweed gins patented by Berkman, gently crushed the pods to release the floss, which was separated from the seeds and husks, baled, and shipped to the vest manufacturers. For the length of a war, a small Michigan town reigned as the milkweed capital of the world, a crown as improbable as it was short-lived.
The USS Indianapolis and the share of uncertainty
History has kept a chilling scene. On July 30, 1945, the cruiser USS Indianapolis, which had just delivered components of the first atomic bomb to Tinian, was ripped open by torpedoes from a Japanese submarine and sank in twelve minutes. Nearly nine hundred men survived the sinking, then drifted for days in the Pacific, without enough rafts, at the mercy of thirst, sun and sharks. For many, between life and the abyss, there was only the fabric of a life vest.
Were those vests filled with milkweed floss from Petoskey? Several survivors have said so, as has the Petoskey museum. A Wisconsin volunteer, Beverly Walker, who had picked the plant as a child, met former Indianapolis sailors decades later at a reunion; several told her the fibre in their vests had kept them alive. The Navy was indeed filling its vests with this floss at the time, which makes the account credible, even if no archive allows it to be confirmed vest by vest.
What milkweed really delivered
The figures of this epic grow with the years, and it is better to separate two things: the pods picked and the floss actually obtained. On the harvest side, several million pounds of pods gathered by children across the country are often cited, sometimes far more. The floss produced, though, was more modest. According to the Navy's 1946 report, barely 88,000 pounds of floss came off the lines in 1943, and the program, closed in August 1945, totalled only about 1.6 million pounds over three years, far from the five million hoped for in 1945 alone.
The same report does not hide the material's limits. Gathered in the wild, under uneven conditions, the floss offered variable quality and not always the buoyancy promised by the first tests. It mostly filled ordinary vests, sometimes disposable ones, cut for amphibious landings. Then the war ended, and the necessity with it. Asian kapok returned, fibreglass took over, and the 1945 harvest stayed in the fields, with no takers. The Petoskey plant went dark. Berkman fought on to make milkweed a peacetime crop, for clothing or latex, without ever recovering the momentum of the war. His plant returned to the oblivion of the ditches, its army of children sent back to school.
A plant that has already proven itself
There is something striking in remembering that this weed has already, in the midst of turmoil, helped keep men alive. The same hollow, water-repellent fibre that floated in the vests of 1944 warms mittens and coats today. At Lasclay, we read in it a quiet promise: milkweed is only waiting for a good reason to come back, and the war had given it one, brutal and fleeting. This time, the stakes are gentler: recreating the habitat of the monarch butterfly, which depends entirely on it to be reborn each spring.
This post is part of a series on the history of milkweed. Also read: the history of the milkweed industry in Québec, American silk in New France, and the technical feature on harvesting milkweed.
