Is there any item that adds +2 or more to your herblore skll. How do you get it?

evil stew - look in the knowledge base -> manual -> skills -> cooking -> extra features.

thanks, i think im going to sweat out 1 more level though.

evil stew can add up to six levels and greenmans ale (m) adds 2

Does the stew give you +6 each? or is it 0 - 6 levels, randomly?

The stew can add up to 6 lvls (anywhere from 1 to 6)

 

BUT it can also subtract lvls! (all the way to -6)

Your only sure bet is the Greenman's ale (m). It's either brewable (it just depends on luck) or bought from other players.