Herbalism

WoW Cataclysm Herbalism Leveling Guide 1-525

Leveling from 1-70

From levels 1 to 70, we'll gather Silverleaf, Peacebloom, Earthroot and Mageroyal. The best place to start is in Durotar, but if you don't want to travel there you can use any of the beginning zones. For Horde I also recommend Mulgore and Tirisfall Glades. As Alliance, head to Elwynn Forest or Teldreassil. Most herbs are found near mountains, rivers or trees. Most of the time you are safe traveling the edges of zones, along treelines or up and down the edges of rivers to find herbs.
Horde



Alliance

Leveling from 70-150

Once your herbalism reaches level 70, you need to head back to a trainer to learn Journeyman Herbalism. Without question, the best place to level beyond 70 is Hillsbrad Foothills. There is a ton of Mageroyal and Briarthorn surrounding the Ruins of Alterac, which will get you all the way to 150. Once you get to 125, you can go into the Ruins of Alterac and collect Frozen Herbs and Bruiseweeed, these will make 150 come a little faster.
Hillsbrad Foothills 70-150

As an alternative, you can go to the Northern Barrens and collect Mageroyal and Briathorn. At level 125 you should head into Stonetalon Mountains and collect Wild Steelbloom and more Briarthorn to get to 150 faster.
Alternative: Northern Barrens 70-125

Alternative: Stonetalon Mountains 125-150

Leveling from 150-225

You will need to go to an Herbalism trainer to level past 150. To get to 225 you can go to either the Western Plaguelands or to Southern Barrens and then Feralas.
If you choose Western Plaguelands, start by riding or flying around Scholomance as seen in the map while collecting Liferoot. There is a ton of it here and it should get you to at least level 160 so that you can collect Fadeleaf inland. While going from 160-185 stick near the farms and once you hit 185 you can gather everything in this zone. You'll reach 225 very quickly being able to gather all the Khadgar's Whisker.
Western Plaguelands 150-225

Southern Barrens & Feralas is the less ideal route. I wouldn't recommend doing this route unless you have a flying mount. Start by collecting Kingsblood and Liferoot in the northern part of Southern Barrens. You only need to be level 160 before going to Feralas.
Alternative: Southern Barrens 150-160

After Southern Barrens, head south and west to Feralas to collect Khadgar's Whiskers and Fadeleaf until level 225.
Alternative: Feralas 185-225

Leveling from 225-300

Once you've trained Herbalism past 225, you can head to Eastern Plaguelands to level to 275. Around level 260 Khadgar's Whiskers will stop giving you a lot of levels but the Sungrass will suffice to get you to 275.
Eastern Plaguelands 225-275

Once you're 275, head back to town and train Master Herbalism and then fly to the Blasted Lands to reach level 300. In The Blasted Lands you'll find plenty of Gromsblood, Dreamfoil and Mountain Silversage. I actually recommend you go to level 315-330 before leaving, since herbs are more difficult to find in the Outlands. When you're ready to leave, head into the Dark Portal.
The Blasted Lands 275-300

Leveling from 300-360

If you followed the subsequent leveling guide, you should have already trained Master Herbalism and you should be ready to go to Hellfire Peninsula. This guide's focus is to get to 450 asap, so there's really no need to go anywhere else in Outlands unless you need the herbs for leveling Inscription or Alchemy.  Collect Felweed, Dreamfoil and Dreaming Glory in Hellfire until you're level 360. If you get bored in Hellfire Peninsula you can head into Zangarmarsh as early as level 325.

Leveling from 360-380

To continue leveling Herbalism you'll need to train Grand Master Herbalism and then head to either the Holwing Fjord or Borean Tundra and start collecting Goldclover and Tiger Lily. Both of these herbs are valuable on the Auction House. You can make a lot of gold while leveling Herbalism.
If you head to Borean Tundra, you should collect Goldclover until level 375, gather any of the Tiger Lily (requires 375) around the lake in the middle of the zone and then head to Sholazar at level ~380.
Borean Tundra 360-380

If you decide to go to Howling Fjord, collect Goldclover and Tiger Lily until about level 380 and then head to Sholazar Basin.
Howling Fjord 360-380

Leveling from 380-450

At 380 you can head to Sholazar Basin where you can continue picking Tiger Lily and Goldclover until level 400 and then begin picking Adder's Tongue. You won't find a zone full of this many herbs again, so I recommend you stay here until level 450 but you could technically leave at 425.
Sholazar 380-450

Leveling from 450-475

The next step is to learn Illustrious Herbalism from your local Herbalism trainer. Then, head to Mount Hjyal and gather Cinderbloom, Stormvine and Azshara's Veil until you are level 475.
Hyjal 450-475

Leveling from 475-525

Finally, head to Deepholm and collect Cinderbloom and Heartblossom. There are plenty of herbs in Deepholm, but you might be competitive since it's one of the most popular placse to collect these herbs. You need to be level 82 to go to Deepholm. If you're not level 82, you can continue collecting Cinderbloom in Hyjal or Vashj'ir until you are level 500. At level 500, you can go to Uldum and collect Whiptail along the rivers until you're 525.
Deeplholm 475-525