The Grass Menagerie! (Japanese: ハクタイジム！VSナタネ！！ Hakutai Gym! VS Natane!!) is the 37th episode of the Diamond & Pearl.
The time, has come again. Ash is now ready for his Gym Battle with Gardenia, and this time, it's official. Knowing what to expect from her after their last battle, will Ash be able to prune Gardenia's team, or will his team be pushing up daisies?
The heroes came to the Eterna City Gym. The Gym's notability is the amount of grass and trees. Gardenia appears and accepts Ash's challenge. Team Rocket already plans to steal the Pokémon by digging. Gardenia sends her first Pokémon, Cherubi and Ash his Turtwig. Turtwig goes to tackle, but misses and tries with Razor Leaf, though Cherubi evades the attacks, as the sun is really bright. Cherubi fires a SolarBeam, but Turtwig evades and uses Razor Leaf, but Cherubi's speed allows it to fire a SolarBeam and hit Turtwig, negating its attack. Cherubi uses Magical Leaf, but Ash calls Turtwig back. Gardenia tells him it was a wise choice to made.
Team Rocket is digging a tunnel, but they dug into a cave. A miner approaches them, thinking they are also miners. He tells he is digging for treasure - some gems. Ash sends Staravia to battle. Cherubi fires a SolarBeam, though Staravia dodges and retaliates with Wing Attack. Cherubi dodges and goes to fire another SolarBeam, but the clouds cover the sun and it has to wait a while. Cherubi uses Magical Leaf, so Staravia goes up and the leaves dissolve. On Ash's order, Staravia goes slowly down, then charges with Wing Attack. Cherubi goes to dodge, but the sun is too bright to see Staravia and gets hit. With Quick Attack and Aerial Ace, Cherubi is defeated.
Gardenia calls Cherubi back, then sends Turtwig. Ash knows Staravia lost to it, but has a different strategy. Staravia uses Wing Attack, but Turtwig swiftly dodges. Staravia uses Wing Attack several times, but misses all. Suddenly, Turtwig got stuck between trees, allowing Staravia to have a perfect hit with Aerial Ace. Staravia uses Wing Attack, but gets stopped by Leech Seed. Staravia gets defeated by being tackled. Ash sends Turtwig. Team Rocket, meanwhile, still digs. They came on a source and dig more, while the miner collects the gems.
Ash's Turtwig starts by tackling, but misses. Gardenia's Turtwig uses Leaf Storm, but Ash's climbs a tree and jumps away, dodging the attack, then runs around Gardenia's. Ash's Turtwig goes to bite, but gets stopped by Leech Seed. Ash's Turtwig uses Synthesis and Gardenia's goes to stop it with Leaf Storm, but Turtwig jumps to dodge and heals itself completely. Ash's Turtwig retaliates with Razor Leaf and hits Gardenia's. The Turtwig hit themselves with Tackle. The Turtwig are pushed away, but in the end, Gardenia's Turtwig is defeated.
Team Rocket gets lunch as a reward for the digging. The miner goes away with the gems, but Team Rocket does not care, as they have got their stomachs full. Gardenia sends her last Pokémon, Roserade. Turtwig charges, but trips over a trap made by Roserade, Grass Knot. Roserade uses Weather Ball and defeats Turtwig. Brock tells Dawn Weather Ball changes by the weather - since it is sunny, it is a Fire-type. Ash sends his last Pokémon, Aipom. Aipom uses Double Team and charges, but the illusions disappear after they trip Grass Knot, though the real Aipom jumps over and hits Roserade with Focus Punch. Roserade uses Magical Leaf, but Aipom jumps over the trees to evade. However, Roserade's vines grab Aipom and send her to the ground. With Roserade's Flash, Roserade moves away to dodge. Roserade uses Magical Leaf to hit Aipom. Ash calms her down and tells her to hear the move. Aipom's Focus Punch sends the Weather Ball back to Roserade, making a great counter-attack. Roserade uses Magical Leaf, which gets stopped by Swift. The stars spin around Roserade and Aipom's Focus Punch allows the stars to hit Roserade and attack it. With another Focus Punch, Roserade is defeated.
Gardenia is impressed by Ash's team and gives him the Forest Badge. Ash is victorious and pleased about that.
- The title of the episode is a reference to the play, "The Glass Menagerie".
- Turtwig was affected by Leech Seed, even though it is a -type.