I've never been a big fan of the blue Agastache selections like 'Blue Fortune' so I was a bit skeptical when we received 'Blue Boa' to trial. We put it in the ground as a liner in July 2012 and it performed as well as could be expected for a small perennial planted in the middle of summer with little to no irrigation. I've been blown away this season with the flower power of this plant. It is blooming at about 34" tall with dense, showy soft-violet flower heads above fragrant green foliage. This is a drought tolerant perennial once established and looks great in mass or peppered through a perennial border. Keep it on the dry side in a loose, well-drained soil for best results. It begins flowering for us in mid-June and continues for a large part of the summer especially if dead-headed (we don't bother though and it keeps flowering pretty well). 'Blue Boa' makes a great addition to the sunny garden and attracts bees and butterflies and should be hardy to around zone 5-ish I would think.
Follow me @jcramark because life is too short for boring plants.