You emailed me about Tahitian Ginger but I did not know you were talking about Dichorisandra thrysifolia.

Why are you calling Dichorisandra thrysifolia "Tahitian Ginger"? Its not the plant known as Tahitian Ginger at all. Tahitian GInger is a type of ALpinia purpurata which is red and has the only "double" flower known in the A. purpurata group. This is a zone 10-11 plant that must be greenhouse grown in zone 8.

Dichorisandra thrysifolia is actually not a ginger at all but a member of the same family as Wandering Jew, and it will grow in zone 8.