"Garden Day!" is an episode of Oobi from the first season.
Grampu teaches the kids how flowers grow and gives them a seed to plant. After much waiting, they see a sprout emerge from the soil. The kids make up a 'plant, water, and grow' dance based on what they've learned about gardening. — ABC Television
Oobi is in the garden, smelling the sunflowers. Uma walks over to him and asks to smell a flower. After doing this, she sneezes and accidentally blows Oobi away. The next scene shows Grampu and the children with a flowerpot. Grampu teaches them how to plant a seed and explains the process. He tells them to plant the seed, add water to it, give it sunlight, and wait. They use these steps as a kind of mantra to remember the procedure. The children plant the seed in the garden and water it. However, they expect it to grow immediately. They repeatedly chant "Grow, grow, grow!" and notice nothing happening.
Uma pretends to be a seed turning into a flower. She asks the seed to do the same. Kako suggests that it is a dud. Grampu instructs the children to wait longer. Later, Uma is still waiting for the seed to grow. She spies a flower and copies its movements as it is blown by the wind. Later, the children are in the garden when Uma says she is going to hide. The boys then realize that Grampu is coming and that she is planning on hiding from him in plain sight, pretending to be flowers. Grampu sees them immediately, but plays along so they don't feel bad, They jump out and "surprise" him, and he asks if the flower has grown yet, to which they respond no. He offers to check on it again. To their amazement, a sprout has emerged. Grampu tells them that it is similar to a baby flower. The characters take turns saying "hello" to it.
Several days later, the children gather in the garden. Uma gets the idea to play a dance game, doing the "Garden Dance." The three moves are: plant a seed, water it, and watch it grow. After the game, they check on their plant again and notice that it has grown a flower. They watch it in amazement as the episode ends.