Tree Growth Change for single player

I have attempted to change the rate in the cfg files for my local game play. The trees don't change from the planting state to large growth state, instead you chop down little planted state trees. Does changing the maturity age in the cfg not work. I did see some other files that had times related to leaf and branch growth, please tell me I would not have to alter all of those files just to get a reasonable single player experience?

What I have found is if you don't let the chunks "Unload" by traveling far enough away, the trees wont grow to the finished full growth state. You have to travel far enough away that you reload the chunk, then they seem to reach full state.