...an evergreen Zingiber like Z. malaysianum "Midnight"?

I did not think that it was...I have had a plant for a few years that is outdoors and goes dormant in winter like ll the other Z's. But in October, at the fall sale at the local Botanical Gardens, I bought 2 pots full of Z. collinsii and stuck them in the greenhouse. They are still up and still look great. Never went dormant after they bloomed.