1. Herb trader will be back on US realms on 2015/03/28. You can check this on wowhead.
2. Posting here, waiting for a reply, PM'ing the person, getting his btag, .... takes a bit longer (not to mention the spam) than just opening your Premade Finder, clicking on custom and searching for "herb" (on the appropriate day of course). Most of those groups have an auto accept and you'll have your trader in 30s.