3 Gallons should be fine for a while. Eventually the rhizomes will push the edges of the pot. Then either upgrade your pot or divide the rhizomes. A normal pot is fine but if you need to decide on the depth of a pot then shallow is fine (but a regular pot is what I would use). You definitely don't need an extra deep pot.

Unless you plan to dig it up each year you shouldn't put it in the ground. Gingers are tropical, New Jersey is not. They will die if left outside during the winter.

Thankyou Mantisia. I will put it in a 3 gallon pot.
Nila

I've had trouble with squirrels eating my butterfly gingers. No problems with anything else.
Lynn