A tree in Caillou's backyard was damaged by a bad storm and has to be cut down. This makes Caillou sad, but Daddy brings him to the nursery to help choose a new tree. While looking around, Caillou learns about trees and their importance to the environment, the animals, and to humans. After planting the new tree, the birds and squirrels agree with Caillou: he found the perfect tree for their backyard.
