The next day, after they work in the garden, the Vanderbeekers go home to find their father home early and on the couch with a pulled back. They learn from their mother that Mr. Jeet’s condition is unchanged. The children return to the garden, but on their way out, they see Mr. Beiderman at his window. He yells down to the children before throwing down several pairs of new gardening gloves, leaving the children to wonder how he knew about their project.

While working inside the garden, Hyacinth overhears Mr. Huxley with two other men discussing a plan to sell the lot to developers. They mention building luxury condominiums and setting a closing date of July 16, just two days after the children’s planned “Garden Extravaganza.” Distraught, the children try and fail to reach Triple J. That night, they call Isa, who suggests it is just speculation. She advises them to make the garden so beautiful that no one would dare destroy it.

On Saturday morning, the Vanderbeekers encounter Herman near the garden. Herman gives Hyacinth a bag of colorful yarn. Oliver, who dislikes Herman, is suspicious and rudely dismisses him. An upset Hyacinth argues with Oliver about his behavior as they enter the garden.

While digging, Laney finds a small wooden box buried in the dirt. Inside, they discover old seeds and the name “Luciana” carved into the lid. The children realize the box likely belonged to Mr. Beiderman’s daughter, who went to preschool at the church. Though Laney wants to give the box to Mr. Beiderman, the others worry it will cause him pain. Hyacinth, holding the seeds, declares that Luciana would have wanted them to create a garden.

Angie, Orlando, and Benjamin arrive to help spread the soil throughout the lot. The group fills the area with fresh earth and even turns an old toilet and bathtub into planters. They also plant Tilia of the Eternal Spring. Afterward, Jessie worries about how they will afford enough plants to fill the large space.

As they leave the garden, they run into Angie’s father, Mr. Smiley. He sees the empty soil bags in a nearby trash can and recognizes them as the ones from his building. Angie confesses to taking them. At the Vanderbeekers’ apartment, Mr. Smiley and their parents announce the children’s punishment: For the rest of the summer, they must sort all the recycling for Mr. Smiley’s building, beginning the next morning.

The next morning, the children begin their recycling duty in the basement of Angie’s building. They are overwhelmed by the enormous, smelly pile of unsorted bags. After their shift, they receive permission to take some discarded items—tires, paint jugs, two paint buckets, a set of old speakers, and a wooden plank—to use in the garden. Jessie calls Miss Josie at the hospital and asks after her seedlings. Miss Josie is worried about the seedlings dying, and she gives Jessie permission to use or give them away. 

When they arrive at the garden, they find Herman knitting on the church steps. Oliver is rude again, prompting Hyacinth to defend Herman. Upset, Herman leaves. Hyacinth calls Oliver “mean” and bets him $1 million that Herman would want to help if asked. 

After dinner, Oliver and Angie return to the garden to find the gate’s lock broken and the fence damaged. Inside, many of Miss Josie’s seedlings have been trampled, and small pink flags are staked all over the lot. Angie notices two distinct sets of footprints—one from a dress shoe and one from a construction boot.

The next morning, after confirming the damage, the Vanderbeekers analyze the footprints and pink flags, which Oliver explains are used for surveying construction sites. Convinced that Mr. Huxley is responsible, Oliver insists they confront him directly. He knows which building Herman lives in, and they go to the luxury apartment building. Hyacinth identifies Herman’s apartment by its yarn-covered balcony. When Herman answers the door, Oliver accuses his father of vandalizing the garden. Herman is confused until they clarify that they mean the church lot. He then admits he overheard his father on the phone at dinner discussing plans to sell land by the church to a condominium developer.

Hyacinth invites Herman to see the garden for himself, and he agrees. At the lot, Herman expresses remorse for his father’s actions but says that such land deals often fail. He begins pulling the pink flags out of the ground, and the Vanderbeekers join in to help.

The children are discouraged, and Jessie calls for a vote on whether to continue working on a garden that will likely be destroyed. At home, Oliver resolves to vote no. While searching for candy in Jessie’s room, he discovers an acceptance letter to a prestigious science camp. He realizes that Jessie was accepted but lied about being rejected because she knew their parents couldn’t afford the fees on top of Isa’s camp costs.

Moved by his sister’s selfless act, Oliver has a change of heart. He decides the garden is worth fighting for, regardless of the outcome. He goes to the basement and finds his siblings, along with Herman and Orlando, already making planters from recycled jugs. He passionately declares that they must finish the garden for their neighbors and the community. The others agree, revealing they had already decided to continue and were waiting for him to join them.

A week later, the garden has been transformed. Herman donated a strong bike lock for the gate, and the group built a yarn-covered bench. Angie has contributed her father’s neglected houseplants. When Luciana’s seeds fail to sprout, they play Vivaldi’s Four Seasons for them. Orlando has an idea and leads the group to a community garden in the South Bronx that is holding a massive plant sale. Pooling their money, they buy 240 plants and spend the afternoon planting them.

That evening, Mama reports that Mr. Jeet’s condition remains unchanged. Frustrated by the lack of progress, Laney stands on her chair and declares that she is going to the hospital to see him. Her siblings join the protest. Their parents, after a warning about Mr. Jeet’s fragile state, relent and agree to take them all the next day.