well, you cant actually catch turtwig in Pokemon black because it is one of the uncathchable Pokemon because it is Pokemon diamond and pearls starter for the grass type.
the only possible way is to use poke transfer[located near marvelous bridge] on your Pokemon black game if you still have your instruction booklet, that helps.
at the begining of the game the profeser will give you three Pokemon and you have to pick one and those three Pokemon are turtwig chimchar and piplup and if you want turtwig pick turtwig.
It is not possible to catch a wild Turtwig on Pokemon Diamond. It is generally impossible to find and catch Starter Pokemon in the wild. This was a mechanic designed to encourage player interaction for trading.
u cant catch turtwig in Pokemon heart gold unless u have a an action replay code :]
Sorry you can only get turtwig as a starter Pokemon in the begining of the game or have someone trade you a turtwig from their Pokemon diamond or pearl game.
You can't catch a turtwig, you can only get it through a pokemon dream world event
There is no way of getting a Turtwig on Ruby because Turtwig was not created yet when Ruby was released. The only way is to hack.
Turtwig does not appear in Pokemon Sapphire, or in Hoenn for that matter. Instead, you can find Turtwig in Generation IV (Diamond, Pearl, or Platinum).
You can't; you must evolve your Turtwig starter.
If you already have a turtwig then all you have to do is catch a wild chimchar. Get a poke ball (or any other kind of poke ball) and fight till its health is low then catch it.
You tansfer it from earlier generation games
You cannot capture Turtwig in Pokémon Black 2 so the only way to get it in Black 2 is via trading.
you cant you have to start with turtwig and evolve it or trade with someone