You would still have to water because they might get windburn and even when not in the wind, like the shed. Yews or Alberta spruce are good container plants.

Here is a link that might be useful: Propagating Perennials

I have read a bit about this and everything I have read says you have to be sure to water them regularly right up until the ground would freeze as they lose moisture slowly all winter and the container will only have so much water for them to suck up prior to overwintering.
Wish I could be more help.

I grew a white pine in a sooden container on my patio. It did great, but than I discovered a root had come out one of the drainage holes and between the cracks in the flagstones.