(Mark Felsenthal/Mark Felsenthal)

How can a tree promote peace? It can’t even move or speak! But one small tree, or bonsai, symbolizes the friendship between two countries that were once at war.

Sandra Moore and Kazumi Wilds tell its story in “The Peace Tree From Hiroshima.” On Sunday at Busboys and Poets in Takoma Park, they will be talking about how they wrote and illustrated the book. The event helps to kick off the International Day of Peace, which is celebrated across the world on Monday.

For almost 400 years, Yamaki family members tended the bonsai at their home in Japan, close to the city of Hiroshima. A father would take over and teach his son how to water and carefully shape its branches, and that boy would grow up and take over. The pine tree was treated like a member of the family.

Then 70 years ago, something terrible happened. The United States and Japan were fighting each other during World War II, and the United States dropped a nuclear bomb on Hiroshima (and another on the city of Nagasaki).

Thousands of people and animals died in the blast or became sick from the bomb’s radiation. Plants and buildings were destroyed. The bonsai became very weak, too, but the Yamakis nursed it back to health. And in 1976, the family and the Japanese government gave this small survivor to the United States. It was a gift of friendship, for the United States’ 200th birthday.

(Tuttle Publishing)

Moore first saw the tree several years ago at the U.S. National Arboretum in Northeast Washington. An arboretum is a big garden of many kinds of trees, and the peace tree is in a special bonsai collection. (You, too, can visit the tree there.) Moore wanted to learn more about this peace tree so she contacted the Yamaki family.

Just as the story is about a gift of friendship, it also sparked a friendship between Moore and Wilds, her Japanese illustrator. Moore’s home is in Silver Spring, Md. So you might wonder how she and Wilds worked together.

“We talked on the phone and sent countless texts, just like students working on a group project for school,” Moore said. Wilds made pencil sketches and e-mailed them. Sometimes the sketches were so similar to Moore’s ideas that the author wondered how the illustrator could read her mind from 7,000 miles away.

Wilds knew the area around Hiroshima well. She had raised her two children in the region nearby and had often taken them and her elementary school students to the Hiroshima Peace Memorial Museum.

In her art, Wilds doesn’t show the horrible details of the bombing. Instead, she uses darker colors to set a sad, quiet tone and brighter colors to reveal hope as the city recovers. She wanted “readers to feel nature’s vitality [after] the cruelty of war.”

These two friends finally had a chance to meet when Wilds visited Moore in Maryland and drew sketches of the real peace tree at the arboretum.

“We could talk about the book late into the night,” Moore said. “It felt like a slumber party.”

Or maybe a peace party.

If you go

What: Author Sandra Moore and illustrator Kazumi Wilds will talk about “The Peace Tree From Hiroshima.”

Where: Busboys and Poets, 235 Carroll St. NW, Washington.

When: Sunday, September 20, at 9:30 a.m.

How much: Free.

Ages: Book and event are best for readers 8 to 12.

For more information: A parent can call 202-726-0856 or visit www.busboysandpoets.com/events/2015/9. To visit the peace tree at the U.S. National Arboretum, check out www.usna.usda.gov/Gardens/collections/bonsai.html.

Quattlebaum is a frequent writer for KidsPost and the author of 22 children’s books.