From what I've read, these do well in a container.

Given the height they achieve, how large does the container have to be for the outdoors (Zone 6)?

Thanks!

I would say 3-5 gallon minimum.

Thanks!

I ordered four from a major supplier. Unfortunately, when they shipped, the weather was too cold - but the direction said to plant right away.

None of them survived but I'll know better this spring. I'll keep them inside until June.