at the bottom of the solaceon ruins, left of soleceon town
youdon't defog is a hm move that is in Pokemon diamond, pearl, and platinum
You get the HM Defog in the Solaceon Ruins.top of lost tower
It is at the top of the lost tower. An old lady will giv it to you.
It Is Impossible To Move Pokemon, From Pokemon Blue Or Pokemon Silver To Pokemon Platinum Version.
The route east from Veilstone city. TIP: bring Defog and Rock Climb!
You need the HM Defog which is in the Safari Zone. Then you need to teach it to a flying-type Pokemon on your team (it is a flying type move). Keep this Pokemon in your party and you should be able to get past the grunts
On Pokemon platinum, you cannot move or migrate Pokemon from Pokemon silver or Pokemon blue version. It can only be done from the Gameboy advanced games. Those are Pokemon Ruby, Sapphire, and Emerald version.
Use the move Defog.
The HM move Defog allows the trainer to clear the road ahead of any mist or fog. The fog makes it hard to see where you are going in the game, and also lowers your Pokemon's accuracy in battle. The move Defog in battle lowers the target Pokemon's evasiveness. HM05 Defog can be learnt predominately by Flying-type Pokemon.
I suggest you bring a Pokemon that has the move defog,and then use defog to see better while in the cave.
defog is no longer a hm move but if you want to get rid of it go to the place with fog on your birthday
Defog did not become a move until Generation 6 so you will not be able to find it in LeafGreen