Impressive as the intense flower color is, it disappears when the plants are viewed from any distance. And it takes a lot of flowers in this color to make much of a splash. But there is a real sense of satisfaction to be had in viewing such a vibrant blue in the garden.
It has taken a while for me to become comfortable with the idea that this is a reliably hardy perennial in our climate. But local gardeners have been growing this plant for at least twenty years that I know of. If we go back to having severe winters, perhaps we'll lose them; but for now, I'm using this plant freely in some of the borders.
The one shown in the image above is the one called 'Black and Blue'. I also grow the form with a green calyx and the same intense cobalt corolla color. The pale blue of 'Argentine Skies' is a lovely color, too, but it does not move me the way the cobalt-colored forms do.