You don't.
you get groudon from a certain fossil
Groudon isn't in Pokemon Pearl. The only way to get Groudon is to trade it from the GBA game, via Pal Park, or to cheat.
Go into the groudon cave and beat team magma. and then catch groudon with ultra ball or timer ball.
the only way to get groudon is to either import it from Pokemon sapphire/ ruby/ or emerald, OR, trade it from pearl/diamond/or platinum.
groudon is in pal park in the mountain area
You can't
No.
You can not get groudon in Pokemon pearlYou can get it through migrating from ruby, sapphire, or emerald.
There is no real way to get groudon, but you can just migrate it, or have a friend trade it to you.
Migrate a level 100 Groudon from Emerald or Ruby is the only way I know of.
Yes
Groudon doesn't show in Pokemon Sapphire just like if you buy Pearl, Dialga won't show up in it.