You are probably right i already thought about doing that it will probably be the best optionAnd Vitor, I am sorry but it definitely sounds like your best option would be to plant tree's directly into the ground while you are away at school. It sounds like your limiting factor is the trees being poorly monitored for water. After you graduate you can pot them up and start the fun stuff, you'll be glad you planted all those trees when you have nice thick trunks to play with.