growing ginger in zone 5

Your chances are roughly midway between Buckley's in the natural environment of zone 5. I found the ref article vague and fluffy with very little substantial information, I wouldn't get too excited about this.

David

The ginger used in cooking and shown in the Web page you cite is Zingiber officinale. It's hardy to about 22F. It requires heat and high humidity in the summer.

Shell ginger (an ornamental) is part of the genus Alpinea. They are hardy to about 15F. They require shade and protection from winds.

Ginger lilies (another ornamental) are in the genus Hedychium. They are hardy to about 20F and also require high humidity.