Bulbasaur's Mysterious Garden (Japanese: フシギダネのふしぎのはなぞの Bulbasaur's Mysterious Flower Garden) is the 51st episode of Pokémon: Indigo League.
After a fight with a Rhyhorn, Ash's Bulbasaur seems to be evolving. During the night, Bubasaur goes to the Mysterious Garden, but decides not to evolve. This does not please Venusaur and the Ivysaur. When Team Rocket capture all the Ivysaur, the sun rises and enhances Bulbasaur, allowing it to make a counterattack!
Ash and his crew are still on a tough path to Cinnabar Island. After battling his way through many trainers, he comes across a Hiker. This dangerous trainer decides to battle Ash and sends out his Rhyhorn. Ash, accepting his challenge, sends out Bulbasaur. Bulbasaur, unwilling to give up endures Rhyhorn's strength and defeats it. After the two trainers chat, Ash finds out that Bulbasaur isn't feeling so well and the bulb on his back starts glowing. The worried Ash brings Bulbasaur to the Pokémon Center to have Nurse Joy examine him. After examining him, Nurse Joy tells Ash it's preparing to evolve, this making Ash very exited. After showing them a garden of blooming flowers, Joy than informs the friends that Bulbasaur gather from all over the world to attend a festival where they evolve. The festival takes place in the "Mysterious Garden". Bulbasaur overhears all of this.
That night, Pikachu wakes up to see Bulbasaur walking out of the Pokémon Center. Pikachu follows Bulbasaur all the way to a garden where some other Bulbasaur pick him up with their vines. Pikachu trys to help Bulbasaur, but he makes Pikachu stop. Pikachu than races back to the Pokémon Center to get Ash. He wakes Ash up and leds him to where Bulbasaur was. Meanwhile, Team Rocket finds the group of Bulbasaur and trys to capture them. This ended in no positive results. Back near the Pokémon Center, Ash, Misty and Brock follow the pollen to try and find Bulbasaur. However, vines try and block their path. Eventually, they find a garden filled with Bulbasaur. These Bulbasaur than start chanting and all of the pollen goes directly to a tree, making it grow very high. A Venusaur than emerges from inside the newly-grown tree. After chanting some more, this time with Venusaur, the Bulbasaurs all start to evolve into Ivysaur.
Ash's Bulbasaur wasn't chanting, so he did not evolve yet. Ash, starstruck by the sight of evolution, wonders if his Bulbasaur is going to evolve. His Bulbasaur is trying not to evolve, much to Ash's surprise. Venusaur get upset at Ash's Bulbasaur as Ivysaurs said that he made him upset and Venusaur used Vine Whip on Bulbasaur, but Ash interrupts and takes the hit for Bulbasaur. Ash apologizes for showing up, as humans are not allowed, but he know that he has to protect his friend.
Venusaur trys to convince Bulbasaur to evolve by manipulating nature, but Team Rocket enters the forest via balloon. Team Rocket starts sucking up all of the Ivysaur and the Venusaur. Ash commands Bulbasaur to "blow them out of the sky", but he fails. The sun's rays start to shine on Bulbasaur's bulb and Dexter the PokeDex informs Ash that it is preparing to use Solarbeam. Bulbasaur blasts Team Rocket to oblivion with his new attack and free all of the Ivysaur. Team Rocket falls out of their balloon and all of the other Pokémon want revenge on Team Rocket. They all smack Team Rocket with their vines and make them "blast off again". Venusaur then lets Bulbasaur leave and is now okay with him not evolving. Ash and his crew continue their quest to reach Cinnabar Island.
- The "Who's that Pokémon?" in this episode is Ivysaur.
- James breaks the fourth wall by saying their fans expect their motto.