almost anything will work, if it is light colored and has good drainage. In cooler climates, avoid anything like terracotta that is porous, as the evaporation will cool the soil; and citrus roots don't like to grow into cool soil.

I agree with John. I live in Zone 6 and I use plastic bucket with holes drilled in the bottoms and side for aeration and cooling for summer. I use packing tape on the most of the side holes in winter to limit evaporative cooling of the soil. Anything will work if you are willing to move the weight if needed from season to season.

cocolocomoco I am now home and can show with detailed pictures of what I have done for my customers and my myself.

In my opinion the best of the best for growing trees in a container, is to grow them in an Air Root Pruning container. They are unbeatable for developing an outstanding root system, thus an outstanding tree. - Silica