Hi Gaza, there was a good discussion on this subject a few months ago at
http://forums.gardenweb.com/forums/load/ginger/msg0710142810714.html?7

I think the general conclusion is that this one is very difficult to bloom in containers no matter how mature, but Bihai has had very good luck blooming it when it is planted in the ground in her greenhouse. She posted a beautiful photo of it.

Dave Skinner
www.gingersrus.com