Where do you catch pinecone on soul silver?

You can catch Pineco in SoulSilver by headbutting a headbut tree. These trees can be found all over. the ones that are separate from the others are the ones with Pokemon in them. If the tree you headbutt doesn't have a Pokemon in it then it wont ever, no matter how many times you headbutt it. (www.serebii.net has almost anything you could possibly need on Pokemon)