"Over-potting" is a term that arises from a lack of basic knowledge about the 3-way relationship between plant material/ soil composition/ container size. It's often parroted that you should only move up 1 size in containers when "potting-up". The reasoning is that the soil will remain wet too long and cause root rot issues. Of course, that's true if you're growing in a heavy, inappropriate soil, but it can be remedied by changing the soil to one that drains freely.

You can grow very small plants in very large containers if you use a very fast soil - with no difficulty and a high degree of vitality - extremely good vitality in many cases.

That said, if you're using a readily available bagged soil, it's better to move up incrementally in container size, or root-prune & return the plant to the same container, than to risk a planting that remains saturated for extended periods because of soil choice.

Al

Thanks tapla for your explanation. I thought i'd be angering the garden gods or committing some sort of blasphemy by overpotting. ;) Thank you for giving me the low down!

What kind of plant are you talking about to be repotting so many times? For years I have started seed in the little 6 pack and never repot, just transplant into garden on into the large containor and that is it. This year though I am starting in the 6 pack and replanting in 16 0z plastic and later I just cut the bottom out of the cup and planted the pot 3/4 of its height into soil and never disturbed the roots, And find that the plant never had any setback from the move like they do sometimes when taking them out of one pot and replanting a root ball that disturbes the roots,