The Outlands can either be a very rewarding place for herbalists, or a place where they get major debuffs. Depends on whether you want to risk it...
Herbalism can be hazardous to your health these days, and not just if you try smoking felweed. (Of course you can smoke felweed -- if you're a troll, that is. They give us special options in the herbalism menu.)
Adept herbalists have discovered that some herbs in Outlands have special properties, including giving you buffs and debuffs when you pick them.