Hey fellas,
I'm not sure how it will work for you being a just a
wee bit colder than here in southern New England (zone 5a) , but I was able to get some fairly decent yields out of my attempt.
Here's a link to my thread on the topic.
https://permies.com/t/266153/Tips-growing-ginger-turmeric-cold#2846988
For what it's worth, I source my rhizomes from Fedco,
https://www.fedcoseeds.com/moose/ginger-and-turmeric]
The order comes with instuctions, but they also list the how-to's online here:
https://www.fedcoseeds.com/resources/growing-guides/ginger-and-turmeric.htm
I had to laugh when I saw the pic on the Fedco instruction page showing the full-grown rhizome ball. I'm here to tell you, it took quite of bit of pruning to clean them up for that pic (see my thread for what they look like coming out of the ground).
Hope this helps - cheers!