First seen by me in a nursery in Seattle. Even in its container it was a sumptuous plant. Rich, emerald green foliage topped with black flower stalks from which emerged some of the best blue flowers I've ever seen. I grabbed three of them and shipped them ASAP... then called a friend to care for them until I returned.
When I got home I planted them in a large triangle configuration in a microclimate space I thought might help them survive an Oklahoma winter. They not only survived that first winter they must have thrived in it... because the following spring tIhey emerged and grew into a substantial plant. They've been in the ground for about ten years by now... and by now they create an enormous, flower filled display. For central Oklahoma gardeners I think 8A is a more reasonable zone map temperature.