I have a number of young Thuja trees that I would like to grow outside my porch.

However, I live in student housing, so I don't like the idea of putting them into the ground - an overzealous gardener / inspector / whatever might decide they are against the fire code or something.

I got myself some wooden boxes that I'd have to isolate in some way (that's a different issue) but my basic question is - are these boxes large enough to house one of the plants, or even two?

Will there come the time when they need an even bigger box? If yes, is there a way to tell before it's too late?

The plants are currently about 3 feet tall (from where the stem enters the soil); the boxes are 1 foot wide, 2 feet long, and 1 foot tall.

I have a number of young Thuja trees that I would like to grow outside my porch.

However, I live in student housing and we're forbidden from altering the outside area, so I don't like the idea of putting them into the ground - I fear that an overzealous gardener / inspector / whatever might have them removed.

I got myself some wooden boxes that I'd have to isolate in some way (that's a different issue) but my basic question is - are these boxes large enough to house one of the plants, or even two?

Will there come the time when they need an even bigger box? If yes, is there a way to tell before it's too late?

The plants are currently about 3 feet tall (from where the stem enters the soil); the boxes are 1 foot wide, 2 feet long, and 1 foot tall.