This Herbalism leveling guide will show you the fastest way how to level your Legion Herbalism from 1 to 100.
Herbalism goes well with Alchemy because you can use the herbs you pick and make potions. But keep in mind, this leveling guide is made to level your profession as fast as possible, so sometimes the herbs you will farm might not be the best for Alchemy.
Learning Legion Herbalism
You can learn Legion Herbalism by simply picking a herb in any of the Legion zones at the Broken Isle.
Get these three items to speed up farming: [Leystone Hoofplates], [Demonsteel Stirrups], [Stonehide Leather Barding].
If you have the 
[Sky Golem], you can use that instead of the Demonsteel Stirrups, and if your class has a tanking spec, you should switch to that while farming, so you won't get dazed and you don't have to use Stonehide Leather Barding.
Don't forget to enchant your gloves with 
[Enchant Gloves - Legion Herbalism]! This enchant brings gathering time down from 1.5 seconds to 0.5 seconds. This is really important if you gather while mounted, because mobs can still interrupt your casting.
1 - 85
Below are two farming routes for Dreamleaf which I think is one of the better zones for leveling herbalism, but you can level in any other zone.
Rest of the farming routes: 
Aethril farming, 
Foxflower farming, 
Fjarnskaggl farming, 
Starlight Rose farming
Val'sharah
This route is for players without flying mount.
If you have flying mount, you might farm too fast and you need to take a bigger loop around the zone to allow the herbs to respawn. So use this map below:
85 - 100
Fel-Encrusted Herb Clusters are orange all the way up to 100, so doing one or two lap at the Broken Shore or Krokuun should get you to 100.
I recommend going to Broken Shore if you have a flying mount. But you can check out my Astral Glory farming guide if you want to go to Krokuun.
Broken Shore
I hope you liked this Legion Herbalism leveling guide, congratulations on reaching 100!