There’s a chain of thought that boxes are cheaper than pots, and are good for training… something midway between putting it in the ground, and a bonsai pot. Here’s a photo to record the idea.
Things to note:
- wide spaces in the floor for draining (this would get covered with wire)
- feet on the boxes so roots die before reaching the ground
- somewhat shallow (I’m guessing 4 inches?)
- simple construction, driven by the side of the planking