(Revised 6 Jan 2016)
It has an airy but not so floppy structure, and it can bloom from August into fall in my area. It is drought tolerance and can take poor soil, but probably more important to also note it is wet intolerance; a survival concern. Full sun is essential as well. The ornamental attributes of Agastache are of interest to me; enough that it is on my new acquisition radar each year.
Agastache ‘Astello Indigo’
I sowed this from seeds. It should be very useful purplish blue flower for garden composition.
Agastache ‘Black Adder’
This is a cross between A. rugosum and A. foeniculum. Its cool bluish purple colour and vertical structure would be very useful for composition.
This delightful Agastache can bloom non-stop from August into November. It only survived a couple of winter, but self sowed a couple of seedlings.
Agastache cana ‘Purple Pygmy’
Its flower colour is more showy than my other Agastaches. Some books rates it as hardy to Zone 7, but it managed to survive a few winters before being killed in a severe winter.
I grew them from seeds, but they appeared to be aggressive sowers. So they were removed after one year of trial even though I kind of like their tall structures.
It is supposed to be a relatively more hardy Agastache. The subtle light flower colour makes it useful accompanying other sun loving plants. It appeared to be killed in the severe winter of 2014, but some new shoots appeared at its base by summer.