As a child, Junot Diaz loved the classic picture book “The Carrot Seed.” Newly arrived in America from the Dominican Republic, he wasn’t yet very good at reading English, and the book — Ruth Krauss’s gentle story of a boy who works hard to grow a carrot, with drawings by her husband, Crockett Johnson — was composed of just 101 words.

Even more than its simplicity, however, Diaz says it was the book’s message that moved him. The boy believes he can get the carrot to grow, but his parents and his older brother aren’t so sure. “I’m afraid it won’t come up,” says the boy’s mother.

“Everyone in my family was completely devoid of patience and forbearance,” explains Diaz. In the book, “the adults said, ‘It’s never gonna grow.’ That spoke deeply in my life.”

Yet Diaz himself grew up to become an acclaimed writer, winning the Pulitzer Prize for fiction in 2008 for his sparkling debut novel, “The Brief Wondrous Life of Oscar Wao.” In 2012, he was named a MacArthur fellow and a National Book Award finalist for his second collection of short stories, “This Is How You Lose Her.”

Five years later, he’s ready to publish his next book. It’s been a long time coming, he knows. And the whole book can be read before bedtime.

“Islandborn” is Diaz’s first foray into the magical world of children’s literature. It tells the story of a young girl named Lola, who is stumped when her teacher asks the students in her class to draw a picture of the place they came from. At the “school of faraway places,” one kid is from the desert. Another is from “a jungle famous for its tigers and poets.”

But Lola can’t recall anything about “the island,” the place where she was born and left when she was very young. So she sets out on a quest to gather the memories of her elders — friends and family old enough to remember. On the island, they tell Lola, there were mangoes and music and beaches where the fish “jump from the waves into your lap.”

Diaz, a creative writing professor at MIT, spent a lunch hour recently at Little Donkey in Central Square, talking about children’s literature and his own love of books. Standing at a communal table, a watch cap perched above his Prada eyeglasses, he agreed with the many novelists before him who have found that writing for children is harder than it looks.

“It’s like any first project — you’re lucky if you hit the target,” he said, sipping a decaf. “Forget the bull’s eye.”

“Islandborn” arose from a promise long ago to the first two of his godchildren, of which he now has six. The girls, who are now in their 20s, asked him to write a children’s book featuring kids who looked like them. Diaz understood. As a young reader he felt “the world I was immersed in wasn’t represented at all.”

So he agreed to do the book, but he didn’t exactly rush.

Though he has no children of his own — at 48, he lives in Cambridge with his longtime partner, the fantasy writer Marjorie Liu — he loves having kids in his life.

“I’ve always been easy and chill with children,” he said. Growing up in an immigrant community, “I had tides of children washing up around me. My mom raised five kids by herself.”

While planning the project Diaz was introduced to his illustrator, Leo Espinosa, who is from Bogota and now lives in Salt Lake City. Espinosa’s colorful style is a perfect example of what Diaz had in mind, he said: “I wanted a retro ’50s style, no ifs, ands, or buts — those classic commercial illustration-type lines that were all over kids’ books at the time.”

Though he’s never written a children’s book, working on “Islandborn” — which will also be published in Spanish — wasn’t exactly a huge stretch for Diaz.

“Throughout my art, I’ve been obsessed with the life of young people,” he said. His first story collection, “Drown” (1996), was a semiautobiographical glimpse into the coming-of-age of Yunior, a Dominican immigrant in New Jersey, trying to make sense of sex and race, abandonment and rebellion.

Yunior is also featured in “The Brief Wondrous Life of Oscar Wao.” He befriends the eccentric title character in part as a way to get with Oscar’s sister, who, like the little girl in “Islandborn,” is named Lola.

“I always knew my neighborhood was a universe,” said Diaz. From the beginning, he envisioned creating an interrelated body of work: “I did want to work at the level of community.”

Cathryn Mercier, director of the Center for the Study of Children’s Literature at Simmons College, says Diaz is right on time.

“This is the topic in children’s books right now: What does inclusion and representation mean? Who should tell the story? What kind of stories do we need to hear?”

Diaz, she says, “already has the authority to tell these stories. That’s huge. He takes a classic, romantic, innocent view of a child and then it complicates it — ‘Who am I? Where am I from? How do I learn about my family and my heritage?’ ”

Though “Islandborn” won’t be published until March, Diaz recently had a test run of the readings he will be expected to make when he was invited to speak with a group of dual-language elementary school students in the Bronx.

The kids tested him, “and I had the best time,” Diaz said. “You ain’t cute to a bunch of kids. Your intelligence is not gonna overwhelm them. Your experience is not gonna count for [anything]. Even at that age, they’re already learning to be too cool for school.”

Teaching future software designers and robotics engineers at MIT has been another welcome challenge, he said. Few of his students have any intention of becoming professional writers, and he wouldn’t have it any other way. They keep him on his toes as he advocates for the value of literature even in — especially in — lives devoted to other pursuits.

“Every class, I have one or two kids who stay behind to talk, and they don’t want to be writers,” he said. “That’s where the culture lives and dies.”

His partner recently noted that Diaz had left the proof pages for “Islandborn” out for their visitors to see. That’s the first time he’s done that for one of his books, she said.

“It’s the first book I’ve enjoyed,” he admitted. “I’m usually either so depressed or tormented by my failures. Holding it makes me happy. To collaborate makes me happy. To collaborate with another Caribbean makes me happy.”

He’s pleased with it because he can imagine a child asking to read it again and again.

“Because the truth of it is: C’mon — who loves a book more than a young person loves a book?”