Wooden grow boxes
I have two three gallon junipers, both are growing upright. They have been in the plastic nursery pots and I either want to put them in the ground or in wooden grow boxes, favoring the boxes. How big should I make the boxes? I was going to go with 1x4 lumber (3/4"x3 1/2") and make the box 12" x 12" x 3 1/2. That appeared to be too small. I also have 1x6 lumber (3/4" x 5 1/2"). I could make them 16" x 16" x 5 1/2". Has any one ever used these or made them? What do you think? I do not want to put them in the ground cause Im doing lots of landscaping and am affraid that I will have to dig them up quite a bit to move them. Also, Im installing irrigation and I do not want to over water these guys. So thats why I favor the boxes over putting them in the ground.
Thanks for your input in advance.