My own Torterra has the moves Crunch, Stone Edge, Earthquake, and Frenzy Plant. Crunch is a descent move with good accuracy. Stone Edge is used to deal with Fire/ice/flying/bug types so it is a must have for torterra.
Earthquake is also good against fire types and is an all around good move since it has high attack power and good accuracy. Now for Frenzy Plant...
Many people dislike it because of the recharge phase after use. However, what I people do not take into account is the fact that it is a great finishing move to quickly end a battle because of the 150 base stat. Also, during normal game play, one can simply switch torterra out if Frenzy Plant fainted the opposing pokemon. This more or less gets rid of the rechaging.
Furthermore, I only use Frenzy Plant when I down to only torterra left, when against a particularly pesky water/ground/rock pokemon, or when the opponent is on his or her last pokemon. Really, Frenzy plant is a great move if one knows how and when to use it.
Sorry for the long explanation.