I use DB rows in order to get that kind of development. I know what you are talking about, the Christmas Tree look, with lats that start at your butt cheek. Another thing to try is single arm cable rows. Sit on a bench in a cable arch with a high pulley. Attach a "D" or "L" handle to it and do basically the same motion as a DB row. Pulling downward at an angle like that really seems to give me some serious emphasis on that area.
Q