I didn't think much about the size of the pot when I planted mine -- except I had a very large pot on the porch with nothing in it -- and I brought the Myer lemon home and put it in there. I'd say the pot was at least 5 times the size of the rootball (pot probably knee high and very wide). This is the first year for it - and I planted it in Sept. It's been in the GH all winter - growing taller and producing tons of little lemons. Maybe it was just "dumb luck" - but I suspect that pot would have been considered too large at the time -- glad now that I don't have to transplant it.