The guys at Naylor's say z5 so I should be OK there. But some of the Arisaema like dry dormant while others are good with moist dormant. I have griffithii var. Pradhanii (zone pushed a bit) which hasn't bloomed in three years and the huge tuber has dwindled quite a bit. I'm planting in coarse compost now with twigs and bark mulch added for better drainage.