Ash's Grotle evolved into Torterra in the episode that's titled "The Fleeing Tower of Sunyshore."
Ash's Grotle evolved in the episode "Aiding The Enemy!". It evolved during a battle with a trainer's Honchrow.
Ash's Grotle evolved into Torterra in "The Fleeing Tower of Sunyshore!", episode 166 of the Diamond and Pearl series and episode 632 overall.
Grotle grotle
Yes, Ash does allow his Turtwig to evolve into Grotle in "Pokémon DP (Diamond and Pearl) Battle Dimension." Ash's Turtwig will evolve into Grotle in the episode that is titled "Aiding The Enemy" whic is episode number 1,148 and according to the Japanese airings it is episode number 100.
I am 20% sure that it grotle should evolve 23 episodes after EP603
you do not need a stone to evolve a grotle. he evolves a Lv.32
A grotle evolves at level 36.
ash's grotle will evolve in the battle againts Cynthia and the elite four
Yes, Buizel will evolve into Floatzel, Chimchar will evolve into monferno, Staravia will evolve into starviraptor, and grotle will evolve into tortera.
Turtwig-18-Grotle-32-Torterra
Grotle evolves into a Torterra at level 32.