I heard that painting the inside of the pot with a copper based paint will prevent the roots from growing to touch the pot, which helps to prevent the tree from being root-bound.
This does work; I've seen it used successfully and tried it myself. The easier, cheaper, less-toxic option is to use fabric pots which also prevent circling roots and create an even better, more-branched root system.
Kevin
I have read about using copper wire wrapped around the base of a plant to prevent slugs and things from slithering up. the copper causes a minute electrical charge, ( probably due to electrolysis ). of course it wont do anything for flying pests. so makes sense that it would work on roots, I have some stuff in fabric pots now, we will see how well these do next year when I transplant. I have 1 small Mangosteen in a big 10 gallon fabric pot, also inoculated , I am doing everything to develop the roots on this plant. its only been in the pot a month and already has pushed out new set of leaves. so I am guessing it is happy.
