World War II was the backdrop to my childhood. The war had ended just before I was born, but when I was a child, adults often discussed their war experiences, both in the military and on the home front. I learned, of course, about Victory Gardens. Many of those plots were still in use a decade or more after the war ended.

So I knew, when I first learned about it last winter, that I had to read “Plants Go to War: A Botanical History of World War II,” which was published in late 2019. And I was excited when the Garden Club Federation of Maine selected the book’s author, Judith Sumner, to speak at its virtual fall conference in October.

Victory gardens, under different names, were grown in all the nations in the war, on both sides. In Germany and Britain, many gardens were planted in areas where bombs had cleared the land.

Officials did not want people to grow just any food though. In 1929, a biochemist and a physician shared a Nobel Prize for the discovery of vitamins. With that newfound knowledge, people were encouraged to grow vitamin-rich food: squash, carrots, radishes, cabbage and the like. Cucumbers and watermelon were discouraged because they took up a lot of space but lacked nutritional value.

Everyone praises victory gardens now, but not everyone supported them at the time. Commercial farmers worried about competition. Some worried that the soil in urban gardens was too polluted to produce healthy food. And seeds were in short supply. In her talk, Sumner said that many seeds planted in America were produced in Holland; when Germans occupied that country, the supply dried up. But here in America, when Eleanor Roosevelt planted a victory garden at the White House, most of the opposition ended. Soon, gardens popped up everywhere. By 1944, Sumner said, 40 percent of the vegetables eaten in America were grown in victory gardens at homes, schools or workplaces.

Those victory gardens were quite unlike the vegetable gardens people tend now. The goal was productivity, so the use of chemical fertilizers and pesticides was highly recommended to increase production.

The role of plants in war went way beyond the victory gardens. Plants were also needed to produce medicine, building materials, clothing, ropes for all kinds of uses and some weapons.

Given that, some decisions by American industry made decades before the war came back to haunt the military. Take quinine and rubber: Though they might not appear to have much in common, both are manufactured from ingredients in trees native to South and Central America. But U.S. manufacturers instead were growing the trees on Pacific islands, because it cost less. During the war, those islands came under the control of Japan.

Quinine comes from the feverbark tree, with the botanical name Cinchona, and was needed to treat malaria, common in tropical areas. The rubber tree, Hevea brasiliensis, produces rubber needed for multiple military uses. To get needed rubber, some of the South American plantations were revived. But as the war progressed, substitutes were created for both quinine and rubber. One substitute for rubber was, of all things, dandelions.

The most important crop grown during the war was cotton, Sumner said, which was needed for clothing, tenting, parachutes, twine and cords. The military vastly increased the amount of cotton grown during the war. Sumner noted that German prisoners of war tended and harvested much of the U.S. cotton, especially in the fields of Oklahoma and Texas. Jute and thistle, the material traditionally used to make rope, is tropical and grew in areas controlled by the enemy. To substitute for it, the U.S. turned to growing hemp.

There was a hitch: The move “Reefer Madness,” about the dangers of marijuana, had come out just before World War II. In 1942, the government produced another film, “Hemp for Victory.” As a precaution, it assigned guards to the hemp fields to make sure people didn’t take the plants for illegal uses.

These are just a few of the many fascinating details in “Plants Go to War,” which was a great read during the dark days of COVID, and would be a great read anytime.

Sumner, who lives in Worcester, Massachusetts, is now taking a deep dive into botany and a different war; she is at work on a book about plants and the American Civil War.

Tom Atwell is a freelance writer gardening in Cape Elizabeth. He can be contacted at: tomatwell@me.com.