@bubk50
I, too, have started plants indoors and have run into that same problem! I would agree with what the other folks have said. Currently, I start my seeds in 5" peat pots from Jiffy.(the peat is sustainability harvested)
For plants that I started in 3" pots that have become root bound, I pot the entire 3" peat pot into the larger 5" peat pot. This has worked out for me for the last couple years. Doing this prevents the roots from being disturbed as you can still just put the whole 5" pot in the ground.
Good luck!
